Helminth Parasites Research Articles

T-helper cell phenotypes are repeatable, positively correlated and associated with helminth infection in wild Soay sheep

Abstract Background T-helper (Th) cells co-ordinate immune responses to ensure that infections with diverse parasites are controlled effectively. Helminth parasites such as gastro-intestinal nematodes (GIN) are generally associated with T-helper type 2 (Th2) responses, while intracellular parasites are associated with Th1 responses. Although laboratory models have reported that Th1 and Th2 can be antagonistic, this has been challenged by studies of natural infections. Methods Between 2019 and 2022 we completed 759 captures of 538 wild Soay sheep (1-4 captures per animal) and monitored body weight, parasite egg counts, Th phenotypes, cytokines and GIN-specific antibodies. Results While different Th cell counts, cytokines and antibody isotypes were generally positively correlated with each other, no strong positive associations were observed between these measurements. Cell counts had low repeatability (among-individual variation) across four years, while antibody levels were highly repeatable. The Th1 and Th2 cytokines IFN-γ and IL-4 were moderately repeatable and were positively correlated at both the between- and within-individual levels independent of body condition or parasite exposure. IL-4 was negatively associated with GIN faecal egg count, while IFN-γ was negatively associated with coccidian faecal oocyst count, suggesting that these cytokines reflect resistance to these parasites. None of our immune markers were strongly associated with lamb survival. Conclusions Our results provide insights into how different aspects of immune function interact to produce effective responses to complex infections but suggest longer term data collection is required to address the causes of these interactions and to detect fitness consequences of variation in T cell phenotypes under natural conditions.

IL-4 induces CD22 expression to restrain the effector program of virtual memory T cells.

Parasitic helminths induce the production of interleukin-4 (IL-4), which causes the expansion of virtual memory CD8+ T cells (TVM cells), a cell subset that contributes to the control of coinfection with intracellular pathogens. However, the mechanisms regulating IL-4-dependent TVM cell activation and expansion remain ill defined. Here, we used single-cell RNA sequencing of CD8+ T cells to identify pathways that control IL-4-dependent TVM cell responses. Gene signature analysis of CD8+ T cells identified a cell cluster marked by CD22, a canonical regulator of B cell activation, as a selective surface marker of IL-4-induced TVM cells. CD22+ TVM cells were enriched for interferon-γ and granzyme A and retained a diverse TCR repertoire while enriched in self-reactive CDR3 sequences. CD22 intrinsically regulated the IL-4-induced CD8+ T cell effector program, resulting in reduced responsiveness of CD22+ TVM cells and regulatory functions to infection and inflammation. Thus, helminth-induced IL-4 drives the expansion and activation of TVM cells that is counterinhibited by CD22.

Molecular uncovering of important helminth species in wild ruminants in the Czech Republic

Monitoring gastrointestinal helminth infections in wild ruminants poses significant challenges for managing wildlife health, particularly regarding invasive species. Traditional coprological methods are often limited by their labor-intensive nature and potential for erroneous identification due to morphological similarities among parasite species. This study employed advanced molecular techniques to assess the prevalence and distribution of several helminth taxa, including the invasive nematode Ashworthius sidemi and the trematode Fascioloides magna, in wild ruminant populations in the Czech Republic (CR). A comprehensive and extensive survey on parasite occurrence, unique in its nationwide scope, was conducted on 983 fecal samples collected from red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama), and mouflon (Ovis musimon) across various regions of the CR. The samples were analyzed using multiplex real-time PCR assays specifically designed to detect the DNA of six helminth representatives: the nematodes A. sidemi and Haemonchus spp., as well as the trematodes F. magna, Dicrocoelium dendriticum, Fasciola hepatica, and Calicophoron daubneyi (and representatives of the family Paramphistomidae, respectively). These assays targeted regions of ribosomal DNA (rDNA) and were designed to exhibit high sensitivity and specificity, enabling accurate detection of helminth parasites directly in fecal samples. The molecular assays revealed that invasive nematode A. sidemi was the most prevalent helminth species, detected in 15.8% of all samples (155/983), with the highest infection rate observed in red deer at 30.7% (124/404). Haemonchus spp. were also frequently detected, identified in 14.9% of samples (146/983), particularly in roe deer, with a prevalence of 23.2% (86/371). Spatial analysis of these nematodes across various regions of the CR revealed the extensive distribution of both A. sidemi and Haemonchus spp. in nearly all regions. In contrast, trematode infections were less common, with F. magna and D. dendriticum each found in only 1.5% of samples (15/983). Members of the family Paramphistomidae were detected in 0.2% of the samples (2/983) and were confirmed through sequencing as C. daubneyi. The geographical distribution patterns identified in this study indicate potential hotspots for specific helminth species. These findings are critical for planning health management and conservation strategies to mitigate the impacts of helminth infections, especially in areas affected by invasive species.

Microtubule inhibition as a proposed mechanism for the anthelmintic effect of phytochemicals isolated from Cicerbita alpina

The alpine plant Cicerbita alpina (L.) Wallr., when grown as a sprout, is known as a bitter-tasting culinary delicacy. Recently it has also been reported to have anthelmintic activity, prompting further investigation into its mechanism of action. Liquid–liquid fractions were prepared from a methanolic extract of the aerial parts and were submitted in parallel to embryo development (ED), worm motility (WMT), and cytotoxicity assays for anthelmintic and toxicity evaluations. The anthelminthic assays revealed the more polar fractions to be most active against Ascaridia galli embryos (BuOH | 68% ED | c = 500 µg/ml and EtOAc | 65% ED | c = 500 µg/ml) and Caenorhabditis elegans adult worms (BuOH | 49% WMT | c = 150 µg/ml and EtOAc | 74% WMT | c = 150 µg/ml) suggesting the fraction’s constituents possess dual anthelmintic activity against multiple life-cycle stages (i.e., eggs, worms) of helminths. Additionally, the BuOH fraction was non-cytotoxic to human cell-lines. Subsequent FCC and SEC derived subfractions were submitted to the anthelmintic assay workflow and the enriched subfractions B1 and E3.8, phytochemically assigned as 11-β,13-dihydrolactucin and luteolin, demonstrated bioactivity against the embryo phenotype (B1 | 58% ED | c = 1.8 µM and E3.8 | 46% ED | c = 1.7 µM) within range of the flubendazole control. Furthermore, luteolin was found to inhibit C. elegans egg hatching (luteolin | 65% EH | c = 10 µM | t = 10 h) within the range of the control albendazole. Both identified anthelmintic phytochemicals were found to affect tubulin polymerisation at a concentration of c = 50 µM. Together with in silico virtual screening studies, these results suggest microtubule stabilisation as a possible anthelmintic target and mechanism of action. This work effectively advocates the consideration of C. alpina extracts and fractions for the development of herbal therapeutics against parasitic helminths.

Risks of parasitic helminth disease outbreaks and influence of physico-chemical factors in flood prone areas of Yaoundé, Cameroon.

Urbanization coupled with poverty has promoted the exploitation of risk zones like flood-prone areas in the city of Yaoundé. The overcrowding and poor hygiene observed in these areas are responsible for the unsmiling variations in environmental cleanliness, exploitation of river water for domestic purposes thus putting them at risk for parasitic disease transmissions. This study was conducted in order to assess the risks of human helminthiases outbreaks in relation to water physico-chemical factors in the city of Yaoundé. Water samples were collected monthly from January to June 2022 in 12 stations from 4 rivers (Biyeme, Ebogo, Olezoa and Tongolo) situated in flood plains in the town of Yaoundé. Intestinal parasite resistant forms were identified using the basic sedimentation technique, while water parameters were assessed using standard procedures. Results indicated that rivers in flood-prone areas are highly contaminated with a 75% prevalence rate. In all, resistant forms of nine parasite species were recorded with the genus Toxocara being the most diversified with two species. Strongyloides stercoralis was the most prevalent (33.3%) and most abundant (1269) species followed by Toxocara canis (26.4%), Ascaris lumbricoides (25%), Toxocara leonina (20.8%), Hookworm (15.3%), Trichostrongylus sp. (11.1%), Diphyllobothrium latum (8.3%), Trichuris trichiura (2.8%) and Schistosoma intercalatum (1.4%). The least abundant species was Trichuris trichiura (33). Higher densities of parasite resistant forms were observed during the dry season. River Tongolo was the most contaminated with pathogenic forms. Water pH, orthophosphate, organic matter and alkalinity revealed negative corelations with the occurrence of Diphyllobotrium latum (r=-0.375, -0.253, -462, -0.448 respectively) while organic matter and pH showed positive correlations with the occurrence of Strongyloides stercoralis (r=0.378) and Trichostrongylus sp. (r=0.238) respectively. Flood areas constitute a potential risk zone for the maintenance and spread of human helminthiases. Maintaining proper personal cleanliness, environmental sanitation through the building of functional and accessible faecal disposal facilities and drainages and abstaining from using the rivers as waste dumps are essential in this area to prevent parasitic helminth disease outbreaks.

Gastrointestinal helminth of Nile crocodiles (Crocodylus niloticus), in Arba Minch Crocodile Ranch, Ethiopia

Parasites are among the major organisms that affect the health of crocodiles. A cross-sectional study was conducted from November 2021 to May 2022 aimed to determine the prevalence of gastrointestinal helminths of Nile crocodiles in Arba Minch Crocodile Ranch (AMCR), Ethiopia. A total of 322 fecal samples were collected using a random sampling technique. Standard parasitological tests were used to identify the gastrointestinal helminth parasite. Out of 322 fecal samples examined, 102(31.68%) were found positive for gastrointestinal helminths. Among the endoparasite eggs detected Dujardinascaris (18.01%) species was the most dominant species followed by Trichinella species (5.62%), polydeliphs (3.1%) and Renifers species (0.62%). There was a statistically significant difference(P = 0.0001) in the prevalence of helminth parasites between male (15.97%) and female (44.38%) crocodiles. Likewise, the prevalence of helminths between different age groups was determined with the highest prevalence in crocodiles of less than 8 years old (41.9%) and the lowest prevalence in crocodiles of age greater than 11 years (19.56%). It has been observed that the crocodile in the area of study had mixed infestation with more than one parasite. The study revealed that gastrointestinal parasites were prevalent in the ranch. Therefore, strict prophylaxis treatment and hygiene should be performed in the study area.

Helminth parasites of Galápagos mammals: A new cestode of the genus Raillietina from the endemic rice rat Nesoryzomys swarthi and a summary of parasites from both endemic and invasive rodents.

Helminth parasites of Galápagos mammals: A new cestode of the genus Raillietina from the endemic rice rat Nesoryzomys swarthi and a summary of parasites from both endemic and invasive rodents.

Bibliometric analysis of neutrophil extracellular traps induced by protozoan and helminth parasites (2008–2024)

IntroductionParasitic diseases pose a significant global public health challenge, affecting billions of people and causing substantial economic losses in livestock and poultry. In the fight against these infections, neutrophils play a crucial role, employing various strategies, including the release of neutrophil extracellular traps (NETs). Recent studies have made significant progress in understanding NETs triggered by protozoa and helminths. However, a comprehensive bibliometric analysis that compiles these findings and identifies research hotspots and trends in this field is still lacking.MethodsWe utilized the Web of Science Core Collection and Scopus databases to retrieve original articles on NETs induced by protozoa and helminths. After screening, the data was transferred to the visualization tools VOSviewer, Biblioshiny, and CiteSpace for analysis.ResultsOur study included 159 original articles published in 69 journals, involving 909 authors from 270 institutions across 41 countries. Germany and Brazil have made the most significant contributions to the research on NETs and parasites, accounting for 45 and 32 publications, and 1,495 and 1,342 citations, respectively. Carlos Hermosilla and Anja Taubert (Justus Liebig University Giessen, Germany), and Elvira Saraiva (Federal University of Rio de Janeiro, Brazil), are leaders in the field, both in terms of publication output and citations. Frontiers in Immunology has consistently and significantly impacted the field, and an article in the Proceedings of the National Academy of Sciences of the United States of America providing the first direct evidence of NETs release in response to a parasite is by far the most cited. Current research focuses on malaria, Toxoplasma gondii, Besnoitia besnoiti, nematodes, and the mechanisms of NETs production and their effects on parasites and host cells. Emerging trends include therapeutic targeting of NETs and comparative studies across different host and parasite species.ConclusionThis study offers a comprehensive overview and visual analysis of NETs and parasites, highlighting key areas for future research.

Occurement assessment of helminth parasites in Euthynnus affinis from Banten, Indonesia

Abstract. Indaryanto FR, Kamal MK, Butet NA, Affandi R, Tiuria R. 2024. Occurement assessment of helminth parasites in Euthynnus affinis from Banten, Indonesia. Biodiversitas 25: 4978-4985. As an economically valuable fish, Euthynnus affinis requires regular surveillance and assessment of the prevalence of helminth parasitic infestation in Banten waters, Indonesia. In the districts of Cituis-Tangerang (North Banten), Labuan-Pandeglang (West Banten), and Binuangeun-Lebak (South Banten) in the waters of Banten, E. affinis were collected in November 2023 to January 2024. Seven species of helminth parasitic were identified to infect E. affinis in Banten: Anisakis typica (intensity 1.17; prevalence 14.65%), Tentacularia sp. (intensity 1; prevalence 0.64%), Dinurus sp. (intensity 17.75; prevalence 7.64%), Didymozoid sp. (intensity 2.25; Prevalence 7.64%), Rhadinorhynchus sp. (intensity 24.86; prevalence 87.90%), and Acanthocephalus sp. (intensity 24.86; prevalence 87.90%) are the seven species of helminth parasitic that infect E. affinis in Banten. The overall prevalence of helminth parasitic infection was categorized as moderately prevalence (89.17%) with a moderate intensity (27.32). Despite severe infestations of distinct helminth parasitic species, the mean condition factor (K) values for parasitized and non-parasitized fish did not differ appreciably. Positive allometric growth was observed in both parasitized and non-parasitic fish. Helminth parasitic infection exceeding 80 individuals/fish significantly affects the Gonado Somatic Index (GSI). Fish measuring 25-30 cm in total length were found to be susceptible to helminth parasitic infection; however, there was no correlation between fish length and parasite abundance (r2 = 0.0223). Males had a higher infection rate compared to female fish. There was no statistically significant difference in the abundance of parasites across the three locations. The host's diet was found to affect the parasitic infection. The greatest diversity of parasite species was discovered in Labuan, West Banten.

The Role of the Norway Rat, Rattus norvegicus, as a Reservoir of Zoonotic Helminth Species in the City of Barcelona (Spain)

Synanthropic rodents are involved in the transmission of several parasitic zoonoses to humans, such as helminth parasites. As part of a multidisciplinary study concerning the rodent population in Barcelona (Spain), 300 specimens of the Norway rat, Rattus norvegicus, were analyzed to elucidate their helminth community, mainly species with a zoonotic potential. The sample included 263 specimens from the sewage system and 37 from public gardens. A total of 253 (84.3%) rats were found to be parasitized, and 206 (68.7%) harbored zoonotic species. Adult rats were found to be more heavily parasitized with zoonotic helminths than juveniles, but the sex and site of capture had no influence. Six zoonotic helminths were identified: Hydatigera taeniaeformis larvae (1.7%), Rodentolepis nana (8.0%), Hymenolepis diminuta (21.3%), Calodium hepaticum (46.3%), Gongylonema neoplasticum (36.7%), and Moniliformis moniliformis (2.3%). Human zoonotic helminth infections often go unreported, so that the role of R. norvegicus in their transmission is unknown. According to our results, it is advisable to monitor and control rodent populations in deprived settlements close to cities and in cities themselves, and to promote good hygienic and sanitary practices, especially among vulnerable populations and workers with high exposure such as sewage workers.

Helminths infection of Schizothorax niger in Kashmir, India: morphological and molecular characterization.

The identification of helminth parasites in Schizothorax spp. from Kashmir, including Schyzocotyle acheilognathi, Pomphorhynchus kashmirensis, and Adenoscolex oreini, is hindered by morphological limitations and high intraspecific variation. While previous studies have relied on morphological diagnosis, a comprehensive molecular characterization is lacking. To address these limitations and achieve more accurate species identification, this study employs molecular techniques such as DNA sequencing and phylogenetic analysis. Genomic DNA was extracted using standardized protocols. Partial amplification of 18S, ITS, and 28S rRNA was carried out using specific primer sets, followed by Sanger sequencing. Genetic characteristics were analyzed using bioinformatic approaches, focusing on Nucleotide divergence and Phylogenetic relationships. Phylogenetic analysis confirmed the monophyly of S. acheilognathi, revealing close relationships with S. nayarensis. Interspecific variation ranged from 2.0 - 4.1% for 18S and 0.8 - 2.2% for 28S rDNA, while P. kashmirensis showed high genetic similarity to P. tereticollis and P. laevis with variations ranging from 0.1 - 1.5% for 18S and 2.3-6.0% for ITS rDNA. A. oreini forms a monophyletic lineage separate from Caryophyllaeides and Caryophyllaeus species. Our study resolved persistent taxonomic ambiguities within the order Bothriocephalidea, resulting in the reassignment of Schyzocotyle acheilognathi (previously Bothriocephalus acheilognathi) to the reinstated genus Schyzocotyle. This study underscores the utility of ribosomal gene sequencing in characterizing fish parasites and highlights the need for taxonomic re-evaluation of A. oreini within the Capingentidae family.

Reinventing type 2 immunity in cancer.

Our understanding of type 2 immunity has undergone a substantial transformation in recent years, revealing previously unknown functions. Beyond its canonical role in defence against parasitic helminth infections, type 2 immunity safeguards the host through additional mechanisms, including the suppression of excessive type 1 immune responses, regulation of tissue repair and maintenance of adipose tissue homeostasis. However, unlike type 1 immune responses, type 2 immunity is perceived as a potential promoter of tumorigenesis. Emerging evidence challenges this perspective, painting a more nuanced picture in which type 2 immunity might protect against or even actively suppress tumour growth and progression. In this Review, we explore discoveries that highlight the potential of type 2 immunity in reshaping the landscape of cancer immunotherapies.

How Do Trematodes Induce Cancer? A Possible Evolutionary Adaptation of an Oncogenic Agent Transmitted by Flukes.

There is strong epidemiological evidence that development of various cancer types is linked to infection with flukes (Platyhelminthes: Trematoda) in Africa, Asia and the Middle East. The exact nature of the mechanism by which cancer is induced by these parasites is unknown. Here, we provide a new hypothesis suggesting that flukes are not the primary cause of cancer but act as vectors of cancer-inducing microbial pathogens. These pathogens adaptively induce tumours to attract and help flukes to feed on blood from the tumour. Pathogen take-up by fluke vectors also takes place in the tumour; therefore, tumour formation in this case is the result of a mutualistic and adaptive relationship between the microbe and the helminth parasite. The suggested mechanism for cancer induction provided here may help us gain deeper understanding about cancer in general and its relationship with microbes and parasites. By further elaborating the unique nexus between flukes, carcinogenic microbes and cancer, in the future it will also help us to broaden our oncological perspective to reduce human death and suffering from this serious disease group.

Availability, Distribution and Infectivity of Freshwater Snails with Helminth Parasites in Selected Sites of Sokoto State, Nigeria

Distribution of snails was determined from six collection sites of Kware and Wamakko Local Government Areas of Sokoto State. The sampling sites for snail collection were sides or edges of freshwater ponds, slow moving streams, lakes, irrigation canals and rivers found around the villages and towns in which the sampling sites were located. Scoop net was employed in the collection of freshwater snail samples, the collected snails were counted and expressed as the number of snail species per 10 scooping. The snails were identified by the Museum of Natural History, Department of Zoology, ABU, Zaria and using the key to freshwater biology. The snails were taken to laboratory, placed in aquaria with tap water for acclimatization in 48 hours before screening for infectivity with cercariae. Different freshwater snails found from sites of the study were identified as Bulinus globosus, Biomphalaria glabrata, Radix natalensis, Melanoides maculatus, Bellamya cascarillas, Bellamya crawshayi and Lanistes ovum. B. globosus was the species with high number of 46% and distribution while, B. crawshayi was species with low number of 2.8% and least population. The snails were screened for infectivity with cercariae by placing them individually in glass jars (about 10 snails) per aquarium and were exposed to day light for 6 hours. Additional illumination of 100w electrical bulb was provided. The snails were subjected to abrupt reduction of temperature by at least 5oC by placing ice block in the aquarium to facilitate the emergence of cercariae. Three of the seven snail species collected (Bulinus globosus, Biomphalaria glabrata and Redis natalensis) shed cercariae of different morphological characteristics, swimming behaviours and resting positions. Out of the 117 cercariae released, 67 (57.3%) of S. haematobium were isolated from B. globosus, 38 (32.5%) of F. hepatica were isolated from R. natalensis, 12 (10.2%) of S. mansoni were isolated from B. glabrata and non were isolated from M. merculatus the result of the study indicated infectivity of the three snail species and thus, confirmation of their roles as vectors of schistosomiasis and fascioliasis in the study area. Chemical and phytol-molluscicides are therefore recommended to control population of snail vectors as well as the prevalence of schistosomiasis and fascioliasis. Further research on freshwater snail vectors of helminth disease agents is also recommended.

A preliminary microscopic and molecular epidemiological survey of endoparasites within wild-caught and UK captive-bred reptiles: Assessing a potential parasitic disease public health risk?

In the UK, exotic reptiles are increasingly popular as pets, and housed in zoological collections, whilst venomous snakes of medical importance have long been the focus of herpetological studies. As all reptiles can harbour protist and helminth parasites, some of these may carry tangible zoonotic risk. This study utilised traditional and molecular diagnostic techniques, including sedimentation-flotation, real-time polymerase chain reaction (rtPCR), and necropsy, to investigate endoparasite infections in captive-bred (CB) and wild-caught (WC) reptiles. Representative animals originated from pet shops, zoological and private collections as well as those housed in research herpetariums. Parasitic infections were detected in 21.1% (n=109) of samples from 58 reptile species across 12 families. The most prevalent infections included nematodes (17.4%), cestodes (0.9%) and protists (3.7%). The nematodes, particularly strongylid (9.3%) and ascarid (5.6%) species, being the most common. Of particular interest, zoonotic genera, Ophidascaris and Giardia were identified. When possible, necropsy revealed latent infections, including prepatent stages of the hookworm Kalicephalus sp. and pentastomid larvae in Echis ocellatus snakes. These accounted for 55.6% of all parasitic infections. Real-time-PCR methods detected additional co-infection overlooked by microscopy, whilst necropsy provided additional insights. These findings highlight the need in the UK for better parasitic screening protocols to enhance captive reptile welfare, mitigate zoonotic risks and safeguard public health.

New record of parasitic protozoan and helminths in buffaloes from Paraguay

Objective: This study aimed to evaluate the prevalence, abundance, and identification of genera of gastrointestinal parasites in buffaloes belonging to an establishment in Villa Oliva, Ñeembucú Department, Paraguay. Materials and Methods: A total of 117 buffaloes were included in the study and divided into three groups of 39 (n = 39) animals—Group 1: = <12 months (G1); Group 2: = <36 months (G2); and Group 3: >37 months (G3). All samples were tested using the saturated salt flotation. Eggs and oocyte counts were determined using McMaster’s method. Recuperation of larvae 3 was carried out after coproculture using the Baerman technique. Identification was based on morphological identification keys. Results: The presence of eggs and/or oocysts of parasites belonging to Cestoda, Protozoa, and Nematoda was noted. The prevalence of gastrointestinal nematode (GIN) was 36.75%. The highest abundance was observed in G1. After coproculture Moniezia expanza, Eimeria spp., and Haemonchus spp.; Teladorsagia spp./Ostertagia spp. were also identified. It is also observed that the incidence of nematode parasite infestation in female buffalo is high compared to males; however, in terms of microparasites, it is the opposite. According to our results, as buffalo age increased, parasite loads decreased considerably. Conclusion: Those results may link factors between hosts and the environment with the ability to maintain gastrointestinal infestation at levels that do not compromise health and body conditions. This study presented results of the prevalence, abundance, and identification of GINs from buffalos of Paraguay for the first time.

Helminth extracellular vesicles co-opt host monocytes to drive T cell anergy.

Parasitic helminths secrete extracellular vesicles (EVs) into their host tissues to modulate immune responses, but the underlying mechanisms are poorly understood. We demonstrate that Ascaris EVs are efficiently internalised by monocytes in human peripheral blood mononuclear cells and increase the percentage of classical monocytes. Furthermore, EV treatment of monocytes induced a novel anti-inflammatory phenotype characterised by CD14+, CD16-, CC chemokine receptor 2 (CCR2-) and programmed death-ligand 1 (PD-L1)+ cells. In addition, Ascaris EVs induced T cell anergy in a monocyte-dependent mechanism. Targeting professional phagocytes to induce both direct and indirect pathways of immune modulation presents a highly novel and efficient mechanism of EV-mediated host-parasite communication. Intra-peritoneal administration of EVs induced protection against gut inflammation in the dextran sodium sulphate model of colitis in mice. Ascaris EVs were shown to affect circulating immune cells and protect against gut inflammation; this highlights their potential as a subject for further investigation in inflammatory conditions driven by dysregulated immune responses. However, their clinical translation would require further studies and careful consideration of ethical implications.

Unraveling the microRNAs Involved in Fasciolosis: Master Regulators of the Host-Parasite Crosstalk.

Fasciolosis is a neglected tropical disease caused by helminth parasites of the genus Fasciola spp., including Fasciola hepatica (F. hepatica) and Fasciola gigantica (F. gigantica), being a major zoonotic problem of human and animal health. Its control with antihelminthics is becoming ineffective due to the increase in parasite resistance. Developing new therapeutic protocols is crucial to a deeper knowledge of the molecular bases in the host-parasite interactions. The high-throughput omics technologies have dramatically provided unprecedented insights into the complexity of the molecular host-parasite crosstalk. MicroRNAs (miRNAs) are key players as critical regulators in numerous biological processes, modifying the gene expression of cells by degradation of messenger RNA (mRNA), regulating transcription and translation functions, protein positioning, cell cycle integrity, differentiation and apoptosis. The large-scale exploration of miRNAs, including the miRNome, has offered great scientific knowledge of steps in fasciolosis, further scrutinizing the pathogenesis, the growth and development of their strains and their interaction with the host for the survival of the different parasite stages. This review compiles the updated knowledge related to miRNAs involved in fasciolosis and the generated miRNome, highlighting the importance of these key molecules in the host-parasite interactions and the pathogenesis of Fasciola spp. directing towards the development of new biotherapeutic protocols for the control of fasciolosis.

Diagnostic innovations in Equine Parasitology: a Nanogold-ELISA for sensitive serodiagnosis of migratory strongylus vulgaris larvae infections

Strongylus vulgaris, a devastating parasitic nematode in equids, causes life-threatening verminous aneurysms that are challenging to diagnose early. This study pioneered integrating nanotechnology into an indirect enzyme-linked immunosorbent assay (i-ELISA) system to enhance the sensitivity and specificity for detecting S. vulgaris larval antigens in equine serum samples, with PCR confirmation of the species. A conventional i-ELISA and an innovative nano-based ELISA were developed using excretory-secretory antigens from adult S. vulgaris worms. The nano-ELISA incorporated gold nanoparticles (17.4–41.4 nm) conjugated with detection antibodies, enabling remarkable signal amplification. Of the 120 examined equines, 100 (83.33%) were positive for S. vulgaris infection. A conventional i-ELISA and an innovative nano-ELISA incorporating 17.4–41.4 nm gold nanoparticles were optimized using S. vulgaris excretory-secretory antigens. Both assays demonstrated high specificity, with no cross-reactivity against sera from animals infected with other helminth parasites. Remarkably, optical density (OD) readings from both i-ELISAs exhibited a positive quantitative correlation with infection intensity. The i-ELISA OD ranged from 0.45–0.74 (G3), 0.75–0.94 (G2), to 0.95–2.5 (G1). The nano-ELISA showed enhanced signal amplification, with OD ranging from 0.40–0.84 (G3), 0.85–0.99 (G2), to 1.0–3.5 (G1). This nanotechnology-amplified ELISA opens new, highly sensitive, and specific techniques for parasitic diagnosis in equine medicine. Its superior performance, facilitated by signal-amplifying gold nanoparticles, illuminates nanotechnology's potential in revolutionizing parasitological diagnostics for enhanced animal health and welfare management.

Gastrointestinal Helminth Parasites of Heterotis Niloticus (Osteoglossiformes: Osteoglossidae) From Anambra River, Eastern Nigeria

Fish diseases especially those caused by parasites are major problems confronting fish farmers globally. This study investigated the gastrointestinal helminth parasites of Heterotis niloticus (African Bony tongue fish) from the Anambra River basin over 12 months (January to December, 2013). A total of 294 fish were caught from three locations along the Anambra River, and transported to the laboratory for morphological and parasitological studies. Four species of helminth parasites were isolated comprising one cestode (Sandonella sandoni), two nematodes (Procamallanus laeviconchus and Dujardinascaris species) and one acanthocephalan (Tenuisentis niloticus). Out of the 294 fish species examined, the overall prevalence of infection was high (72.8%) with a mean abundance of 0.77 of helminth parasites per fish. Prevalence of helminth infection increased with increasing host weight, although there was no significant relationship (p=0.144). Similarly, there was no significant relationship between the length of fish and helminth infection. The intestine was found to be the site for most of the recovered parasites. More parasites were recovered during the rainy season. It can be concluded that H. niloticus is a new host record for P. laeviconchus. It is therefore necessary to be aware of the parasitofauna for possible zoonotic disease. Keywords: Gastrointestinal; Parasites; Helminth; Heterotis niloticus; Anambra River.