Cestode Parasite Research Articles

A computer model of the distribution of the tapeworm Echinococcus multilocularis in Ukraine

Alveolar echinococcosis, caused by the larval form of the parasitic tapeworm Echinococcus multilocularis, aff ects a wide range of animal species, including domestic and wild livestock, and is a highly pathogenic helminthic disease for humans. Recently developed for the species habitat suitability maps are restricted to the border of the European Union and have left Ukraine outside the scope of this study. Our goal was to model and characterize the large-scale ecological niche of E. multilocularis in Europe, placing a particular emphasis on Ukraine, and to justify an assessment of the risk of E. multilocularis transmission in Ukraine under current environmental conditions. Using the CMCC-BioClimInd dataset and a Bayesian modeling approach, we developed a habitat suitability map for the species in Ukraine and distinguished corresponding risk areas. We anticipate the model will enhance future surveillance eff orts and help to understand the epidemiological situation of the disease, especially under wartime conditions.

Population Dynamics of Cestode Parasite, Gangesia Sp.in Wallago attuof Gomti River, Lucknow, Uttar Pradesh, India

Population Dynamics of Cestode Parasite, Gangesia Sp.in Wallago attuof Gomti River, Lucknow, Uttar Pradesh, India

Extracts and Terpenoids from Stevia Species as Potential Anthelmintics for Neglected Tropical Diseases Caused by Cestode Parasites.

Cestodes are etiological agents of neglected diseases such as echinococcosis and cysticercosis, which are major public health problems. Antiparasitic treatment relies on a small number of approved drugs, which are often only partially effective, poorly tolerated and require prolonged administration. Thus, the discovery of novel potential treatments is critical. The Stevia genus (Asteraceae) includes species that are recognized as a source of bioactive compounds, with many species associated with medicinal uses. In this study, the cestocidal activity of four South American Stevia species that previously showed antiprotozoal activity was analyzed using a motility assay on the laboratory cestode model, Mesocestoides vogae. The four Stevia extracts showed cestocidal activity, with S. alpina var. alpina as the most active. The sesquiterpene lactones estafietin and eupatoriopicrin were purified from S. alpina var. alpina and S. maimarensis, respectively, and tested on M. vogae. Estafietin showed cestocidal activity, inhibiting parasite viability in a dose-dependent manner, even from the first day of incubation. Consistent with the motility effects, the extract of S. alpina var. alpina and estafietin induced marked alterations in the morphology of the parasite. The results of this report show that Stevia species represent a source of new molecules with potential for the treatment of neglected tropical diseases caused by cestodes.

A rare case report on neurocysticercosis – A parasitic disease

Neurocysticercosis is commonly known as cysticercosis, which is the most common parasitic disease of the human nervous system caused by the parasitic tapeworm The development of lesions in the brain and leptomeninges and the consequent onset of symptoms associated with NCC is mainly due to the host immune-inflammatory response. The absolute diagnostic criteria include histological conformation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. It is treated by a course of steroids or immunosuppressants; for intravascular cysts, endoscopic surgery is the procedure of choice as it is minimally invasive.We present a case of 8-year-old female patient who was admitted to the Neurology ward with the chief complaints of loss of consciousness, involuntary movements, headache, fever, and onset of seizures associated with vomiting. She had a seizure episode at the age of 2 years associated with fever, but no treatment was done. She was not on any past medication and was hemodynamically stable. Her lab investigations of magnetic resonance imaging show infective granuloma in the left parietal lobe with mass effect as described above, suggesting neurocysticercosiswhich should be carefully observed at an early stage. We summarized the case report of neurocysticercosis, its diagnosis, and treatment plan.

Isolated Hydatid Cyst of the Breast

The occurrence of primary breast hydatid cysts is exceedingly rare, even in endemic regions, and reported prevalence rates are infrequent. Although classified as a benign condition, it represents a significant health concern caused by the parasitic tapeworm Echinococcus granulosus. Hydatid cyst disease can manifest in various anatomical locations throughout the body, ranging from the head to the extremities. Diagnosis typically involves imaging studies, such as ultrasound, which can reveal the characteristic features of the cyst. Additionally, serological tests may be conducted to detect specific antibodies against Echinococcus. This report aims to present the imaging findings of an exceptionally rare case of an isolated breast hydatid cyst in a 74-year-old female patient.

Endoparasites of rabbits and hares.

Nematode, cestode, protozoan, microsporidian, and pentastomid parasites affect domesticated and wild rabbits, hares, and jackrabbits of the genera Brachylagus, Lepus, Oryctolagus, Pentalagus, and Sylvilagus. Some endoparasite infections are of limited or no significance, whereas others have potentially profound consequences. Accurate identification of endoparasites of rabbits, hares, and jackrabbits is an important facet of the work of veterinary pathologists engaged in lagomorph pathology. Here I review endoparasites from the pathologist's perspective, focusing on pathogenesis, lesions, and implications of infection. Stomach nematodes Graphidium strigosum and Obeliscoides cuniculi are infrequently pathogenic but may cause gastritis and gastric mucosal thickening. Nematodes Passalurus ambiguus, Protostrongylus spp., Trichostrongylus spp., and Trichuris spp. are rarely associated with disease. Adult Capillaria hepatica (syn. Calodium hepaticum) nematodes and non-embryonated eggs cause granulomatous hepatitis in wild Oryctolagus cuniculus and Lepus europaeus, resulting in multifocal, off-white, hepatic lesions, which may be misdiagnosed as hepatic eimeriosis. When the rabbit is an intermediate host for carnivore cestodes, the space-occupying effects of Cysticercus pisiformis and Coenurus serialis may have pathologic consequences. Eimeria stiedai is a major cause of white-spotted liver in O. cuniculus, particularly in juveniles. Enteric coccidiosis is a noteworthy cause of unthriftiness in young animals, and frequently manifests as diarrhea with grossly appreciable multifocal off-white intestinal lesions. O. cuniculus is the natural host for the zoonotic microsporidian Encephalitozoon cuniculi. Infection may be acute and focused mainly on the kidneys, or it may follow a chronic disease course, frequently with neurologic lesions. A latent carrier status may also develop.

Spinal hydatid disease: A case report

Introduction: The parasitic tapeworm Echinococcus granulosus causes cystic echinococcosis, also known as hydatidosis. It is a serious medical condition that can show up in a lot of different ways. Although spinal involvement occurs in about 45% of bone echinococcosis cases, it represents only 0.5–4% of all echinococcosis cases. The disease can spread to the spine through hematogenous dissemination, direct invasion, or cerebrospinal fluid seeding from ruptured cysts. While the liver and lungs are the most commonly affected organs, spinal involvement can lead to severe complications, including radiculopathy, motor deficits, and paraparesis. Imaging, such as computed tomography (CT) and (MRI), typically makes the diagnosis by revealing cystic and osteolytic lesions. Case Report: The patient is a 51-year-old male from the Kakheti region (a region in Georgia) who presented with progressive generalized weakness, nausea, vomiting, and lumbar pain. He had a history of spinal echinococcosis, diagnosed 15 years ago, but was unable to complete antiprotozoal treatment due to intolerance to albendazole. Over the years, his condition deteriorated, leading to lower paraplegia and urinary incontinence, necessitating a suprapubic cystostomy. Imaging revealed extensive septated cystic lesions in Th4-S1, which spread to the ribs and subcutaneous tissues. Despite neurosurgical intervention to reduce the cyst burden, the infestation persisted. Multiple hospitalizations were required for complications, such as urinary tract infections and pneumonia. Joint supervision managed the patient’s condition, but he continued to experience spherocyte discharge from numerous fistulas. Conclusion: This case underscores the severe and chronic nature of spinal echinococcal infection, particularly when complete antiprotozoal treatment is not feasible. The patient did not experience severe neurological complications despite the extensive disease burden and the development of multiple vertebral-cutaneous fistulas, possibly due to the continuous drainage of spherocytes. This unusual clinical course highlights the importance of comprehensive management and the potential impact of innovative approaches on managing complex parasitic infections.

Molecular Characterization of Echinococcus canadensis (Cestoda, Taeniidae) in Wolf from the Kirov Region.

This work presents the results of studying the molecular characteristics of parasitic tapeworms Echinococcus canadensis. The helminths were discovered during the autopsy of a wolf (Canis lupus Linnaeus, 1758) killed by hunters in the Kirov oblast in 2021. A molecular phylogenetic study was performed by analyzing the sequence of a fragment of the first subunit of the mitochondrial cytochrome oxidase gene (CoxI). It was found that the detected echinococci belong to the G10 genotype of E. canadensis, which is common in wolves in the northern territories of the Holarctic. We discovered four positions at which the substitutions characteristic only of this genotype are revealed. A substitution at one of the positions that is characteristic exclusively for the representatives of the G10 genotype found in Russia and Finland was also discovered.

Gastrointestinal parasites of owned cats in three districts of Central Ethiopia: Prevalence and risk factors

This present, cross-sectional study investigated gastrointestinal parasites in owned cats was carried out across Bishoftu, Dukem, and Addis Ababa city and towns in Central Ethiopia from February 2022 to April 2023. The primary objectives were to estimate the prevalence and assess the risk factors associated with these parasites. A total of 213 faecal samples were collected and processed using flotation and McMaster techniques. An overall prevalence of 34.7% (74/213) of gastrointestinal parasites was recorded in the examined cats. The cats harboured nematode (14.6%), cestode (12.7%), and protozoan (5.6%) parasites in single (32.9%) and mixed (1.9%) species. Specifically, Toxocara cati, Dipylidium caninum, Taenia spp., Giardia spp., and Physaloptera spp. were the more frequently identified parasites, with prevalences of 9.4%, 8.9%, 3.8%, 2.8%, and 2.8%, respectively. Statistically significant differences (P < 0.05) were observed in the prevalence of gastrointestinal parasites among cats of different sexes, ages, and feeding conditions. Thus, higher prevalence rates were observed in females (49.1%, OR = 2.3), young cats (70%, OR = 4.7), and those consuming uncooked food (40.5%, OR = 3.6). Faecal consistency also showed a statistically significant association (P < 0.05) with the presence of gastrointestinal parasites. However, no significant differences were noted in the prevalence among cats of different housing conditions, seasons, or agro-ecological zones. Cats sharing shelter with families had the highest prevalence of gastrointestinal parasites (52.2%). In conclusion, this study uncovered a notably high occurrence of gastrointestinal parasites in cats in the surveyed regions, emphasizing the imperative of adopting a One Health strategy to address the zoonotic parasites found in cats, which pose significant public health risks.

Antiparasitic activity of the steroid-rich extract of Schima wallichii against poultry cestode.

Schima wallichii Korth., commonly known as the needlewood tree (family Theaceae) has therapeutic uses in traditional Mizo medicine for human helminthiasis and serves as a balm against ectoparasites in animals. Although the medicinal properties have been studied experimentally, its use as a traditional anthelmintic remains unexplored. This study aimed to analyze the chemical components and antiparasitic activity of S. wallichii. The chemical analysis of S. wallichi bark extracts was conducted focusing on the secondary metabolites using petroleum ether, chloroform, and methanol. Gas chromatography-mass spectrometry (GC-MS) was used to identify the specific compounds. An anthelmintic susceptibility test was carried out against Raillietina tetragona, intestinal cestode parasite of fowl. The methanol extract yielded the highest concentrations of alkaloids, carbohydrates, glycosides, sterols, saponins, and tannins among all the extracts. Sterols were the most abundant compounds in all extracts, with flavonoids being absent. Secondary metabolites were largely absent in the petroleum ether and chloroform extracts. The GC-MS data identified cholest-22-ene-21-ol as the major steroid component. The cestode parasite was inhibited in a concentration-dependent manner by the plant extract. The plant extract's anthelmintic activity was evident through observable damage to the parasite's outer structure. Phytosterols in S. wallichii bark are responsible for its anthelmintic properties. The mechanism and pharmaceutical properties of the anthelmintic molecule require further exploration.

Molecular characterization of Bertiella studeri infecting a primate in South India.

Bertiella spp. is a mite-borne cestode parasite that inhabits the small intestine of wide range of mammals, including non-human primates. In the present study, the morphological and molecular analysis of Bertiella studeri recovered from the small intestine of a bonnet macaque (Macaca radiata) from Wayanad, Kerala (South India) was performed. Acetic alum carmine staining identified the cestode morphologically based on the characters like broader proglottids, which contain irregularly alternating genital pores, single set of reproductive organs, 280 testes and a tubular transverse uterus. Molecular characterization was done using 18SrRNA, ITS1-5.8S and COX1 genes. Phylogenetic trees were constructed using MEGA X based on the Maximum Likelihood (ML) method (Hasegawa-Kishino-Yano (HKY) model). Cytochrome oxidase I gene could detect the existence of genetic variation in the parasite from two different hosts viz., monkey (Kerala, Argentina, and Kenya) and human (Sri Lanka). A minimum spanning network of haplotypes was generated by the haplotype networking with the above sequences using the popARTv1.7. Haplotype analysis based on COX1 revealed that the parasite haplotype was different in each country with highest population frequency in Sri Lanka.

Parasite-derived microRNA let-7-5p detection for metacestodiasis based on rolling circular amplification-assisted CRISPR/Cas9.

Metacestodiasis is an infectious disease caused by the larval stage of cestode parasites. This disease poses a serious health hazard to wildlife, livestock, and humans, and it incurs substantial economic losses by impacting the safety of the livestock industry, the quality of meat production, and public health security. Unfortunately, there is currently no available molecular diagnostic method capable of distinguishing cysticercus- and Echinococcus-derived microRNAs (miRNAs) from other helminthes and hosts in the plasma of metacestode-infected animals. This study aims to develop a specific, sensitive, and cost-efficient molecular diagnostic method for cysticercosis and echinococcosis, particularly for early detection. The study developed a rolling circular amplification (RCA)-assisted CRISPR/Cas9 detection method based on parasite-derived miRNA let-7-5p. Using a series of dilutions of the let-7 standard, the limit of detection (LOD) of the qPCR, RCA, and RCA-assisted CRISPR/Cas9 methods was compared. The specificity of qPCR and CRISPR/Cas9 was evaluated using four artificially synthesized let-7 standards from different species. A total of 151 plasma samples were used to evaluate the diagnostic performance. Additionally, the study also assessed the correlation between plasma levels of let-7-5p, the number of Taenia pisiformis cysticerci, and the weight of Echinococcus multilocularis cysts. The results demonstrated that the RCA-assisted CRISPR/Cas9 assay could significantly distinguish let-7 from cestodes and other species, achieving a LOD of 10 aM; the diagnostic sensitivity and specificity for rabbit cysticercosis and mouse E. multilocularis were 100% and 97.67%, and 100% and 100%, respectively. Notably, let-7-5p gradually increased in the plasma of T. pisiformis-infected rabbits from 15 days post infection (dpi), peaked at 60 dpi, and persisted until 120 dpi. In E. multilocularis-infected mice, let-7-5p gradually increased from 15 dpi and persisted until 90 dpi. Furthermore, the expression of let-7-5p positively correlated with the number of cysticerci and cyst weight. These results indicated that the let-7-5p-based RCA-assisted CRISPR/Cas9 assay is a sensitive and specific detection method that can be used as a universal diagnostic method for metacestodiasis, particularly for early diagnosis (15 dpi).

First report on fish-borne Zoonotic cestode larvae of Dibothriocephalus lühe, 1899 in freshwater fish, Oreochromis niloticus (Linnaeus, 1758), from the Hemavati river, Karnataka (India)

The Broad Tapeworm, Dibothriocephalus Lühe, 1899 is a widespread cestode parasite infecting freshwater fishes worldwide and is the causative agent of zoonotic disease Diphyllobothriasis. Freshwater food fish, Oreochromis niloticus (Linnaeus, 1758), is of immense commercial importance and consumed all over the world due to its affordability and palatable nature. The present study records the occurrence of Dibothriocephalus larvae in the intestine of Oreochromis niloticus, collected from the Hemavati River, Hassan district, Karnataka and forms the first report of Dibothriocephalus larvae in Oreochromis niloticus and also forms the first report from Karnataka, India.

Hydatid fluid from Echinococcus granulosus induces autophagy in dendritic cells and promotes polyfunctional T-cell responses.

Parasites possess remarkable abilities to evade and manipulate the immune response of their hosts. Echinococcus granulosus is a parasitic tapeworm that causes cystic echinococcosis in animals and humans. The hydatid fluid released by the parasite is known to contain various immunomodulatory components that manipulate host´s defense mechanism. In this study, we focused on understanding the effect of hydatid fluid on dendritic cells and its impact on autophagy induction and subsequent T cell responses. Initially, we observed a marked downregulation of two C-type lectin receptors in the cell membrane, CLEC9A and CD205 and an increase in lysosomal activity, suggesting an active cellular response to hydatid fluid. Subsequently, we visualized ultrastructural changes in stimulated dendritic cells, revealing the presence of macroautophagy, characterized by the formation of autophagosomes, phagophores, and phagolysosomes in the cell cytoplasm. To further elucidate the underlying molecular mechanisms involved in hydatid fluid-induced autophagy, we analyzed the expression of autophagy-related genes in stimulated dendritic cells. Our results demonstrated a significant upregulation of beclin-1, atg16l1 and atg12, indicating the induction of autophagy machinery in response to hydatid fluid exposure. Additionally, using confocal microscopy, we observed an accumulation of LC3 in dendritic cell autophagosomes, confirming the activation of this catabolic pathway associated with antigen presentation. Finally, to evaluate the functional consequences of hydatid fluid-induced autophagy in DCs, we evaluated cytokine transcription in the splenocytes. Remarkably, a robust polyfunctional T cell response, with inhibition of Th2 profile, is characterized by an increase in the expression of il-6, il-10, il-12, tnf-α, ifn-γ and tgf-β genes. These findings suggest that hydatid fluid-induced autophagy in dendritic cells plays a crucial role in shaping the subsequent T cell responses, which is important for a better understanding of host-parasite interactions in cystic echinococcosis.

Investigating the Taenia solium Fatty Acid Binding Protein Superfamily for Their Immunological Outlook and Prospect for Therapeutic Targets.

Taenia solium, like other helminthic parasites, lacks key components of cellular machinery required for endogenous lipid biosynthesis. This deficiency compels the parasite to obtain all of its lipid requirements from its host. The passage of lipids across the cell membrane is tightly regulated. To facilitate effective lipid transport, the cestode parasite utilizes certain lipid binding proteins called FABPs. These FABPs bind with the lipid ligands and allow the transport of lipids across the membranes and into the cytosol. Here, by integrating a computational with homology protein prediction tools, we had identified five FABPs in the T. solium proteome. We confirmed their presence by RNA expression analysis of respective genes from the parasite's cysticerci transcript. During the molecular modeling and MD simulation studies, two of them, TsM_000544100 and TsM_001185100, were most stable. Furthermore, they had a robust interaction with the IgG1 molecule, as evidenced by MD simulation. In addition, by employing in silico screening, we had identified potential ligand interacting residues that are present on the probable druggable site. In combination with in vitro cysticidal assays, enalaprilat dihydrate showed efficacy against cysticerci, which suggests that FABPs play a significant role in the cysticercus life cycle. Together, we provided a detailed distribution of all FABPs expressed by T. solium cysticerci and the critical role of TsM_001185100 in cysticercus viability.

Taenia solium cysticerci's extracellular vesicles Attenuate the AKT/mTORC1 pathway for Alleviating DSS-induced colitis in a murine model.

The excretory-secretory proteome plays a pivotal role in both intercellular communication during disease progression and immune escape mechanisms of various pathogens including cestode parasites like Taenia solium. The cysticerci of T. solium causes infection in the central nervous system known as neurocysticercosis (NCC), which affects a significant population in developing countries. Extracellular vesicles (EVs) are 30-150-nm-sized particles and constitute a significant part of the secretome. However, the role of EV in NCC pathogenesis remains undetermined. Here, for the first time, we report that EV from T. solium larvae is abundant in metabolites that can negatively regulate PI3K/AKT pathway, efficiently internalized by macrophages to induce AKT and mTOR degradation through auto-lysosomal route with a prominent increase in the ubiquitination of both proteins. This results in less ROS production and diminished bacterial killing capability among EV-treated macrophages. Due to this, both macro-autophagy and caspase-linked apoptosis are upregulated, with a reduction of the autophagy substrate sequestome 1. In summary, we report that T. solium EV from viable cysts attenuates the AKT-mTOR pathway thereby promoting apoptosis in macrophages, and this may exert immunosuppression during an early viable stage of the parasite in NCC, which is primarily asymptomatic. Further investigation on EV-mediated immune suppression revealed that the EV can protect the mice from DSS-induced colitis and improve colon architecture. These findings shed light on the previously unknown role of T. solium EV and the therapeutic role of their immune suppression potential.

Parasitic &lt;i&gt;Cyathocephalus Truncatus&lt;/i&gt; cestodes as an indicator of localization of self-naturalized populations of American char (&lt;i&gt;Salvelinus Fontinalis&lt;/i&gt;) in the Strelka River basin

The Northwestern Federal District holds a leading position in the commercial fish farming of the country. In particular, the Leningrad Region occupies the second place among producers of commercial fish in the region, the fisheries complex of which includes 200 enterprises. The main object of aquaculture is rainbow trout (97.1%). Parasitic diseases often occur in fish farms. To make a diagnosis, a comprehensive examination is carried out, including the collection of epizootological data, a clinical examination, a diagnostic autopsy and laboratory tests. This article describes a case of cyatocephalosis epizootics in an operating fish farming. The causative agent of the disease is Cyathocephalus truncatus cestode, belonging to the order Pseudophyllidea, family. Cyathocephalidae. It parasitizes the pyloric appendages of mainly salmonid fish. The development of C. truncatus occurs with the participation of one intermediate host, which are crustaceans: Rivulogammarus pulex, R. spinicaudatum, Pontogammarus bosniacus, Pontopereia hoi, Pallasea quadrispinosa. To determine the causes of infection of rainbow trout juveniles, an assessment of the infestation of final and intermediate hosts, the seasonality of invasion in 2021-2022, as well as control catches of the head pond and Mill Creek belonging to the Strelka River basin was performed. During the study, 16 individuals of different ages of American char were caught, 6 of them were subjected to a partial parasitological autopsy for infection with cyatocephalosis. As a result of the study, C. truncatus cestodes were exposed in all individuals in an amount from 2 to 5. Consequently, the absence of cases of progenesis in procercoids of intermediate hosts of gammarid crustaceans, infection with parasitic cestode of both final and intermediate hosts allowed us to conclude that the final hosts of the parasite, salmon-like fish species, are present in the enterprise's water supply system. Thus, the parasitic cestode contributed to the self-naturalization of the American char population, the reproduction and cultivation of which in this water source ended in the 1970s, and has been considered lost until now.

Recombinant CD5 and CD6 Ectodomains Induce Antiparasitic and Immunomodulatory Effects in Secondary Cystic Echinococcosis.

Scavenger receptors participate in a wide range of biological functions after binding to multiple non-self or altered self-ligands. Among them, CD5 and CD6 are lymphocyte scavenger receptors known to interact with different microbial-associated molecular patterns, and the administration of the recombinant soluble ectodomains of human CD5 (rshCD5) and/or CD6 (rshCD6) has shown therapeutic/prophylactic potential in experimental models of fungal, bacterial and echinococcal infections. The latter is a zoonosis caused by the larval stage of the cestode parasite Echinococcus granulosus sensu lato, which in humans can induce secondary cystic echinococcosis (CE) after the spillage of protoscoleces contained within fertile cysts, either spontaneously or during surgical removal of primary hydatid cysts. Herein, we have analysed the mechanisms behind the significant protection observed in the mouse model of secondary CE following prophylactic administration of rshCD5 or rshCD6. Our results show that both molecules exhibit intrinsic antiparasitic activities in vitro, as well as immunomodulatory functions during early secondary CE, mainly through Th1/Th17 cytokine bias and promotion of peritoneal polyreactive antibodies. These data support the relevance of the parasite components bound by rshCD5 and rshCD6, as well as the potential of their prophylactic administration as a useful strategy to reduce secondary CE in patients.

Intestinal helminth parasites of Felis catus in Syangja, Nepal

Domestic cats can be infested by a huge range of parasite species, leading to a range of diverse clinical signs and symptoms. However, a comprehensive understanding of these endoparasites, particularly in the context of multiparasitism, remains limited. The aim of the study was to determine the prevalence of intestinal helminth parasites on domestic cats in Arjunchaupari Rural Municipality of Syangja District, Nepal. The study was carried out from November 2017 to June 2018. A total of 30 fresh feline fecal samples were collected and examined by using the Saline wet method and sedimentation technique. Overall, 21 (70%) fecal samples were found to be positive for different parasitic infections. Four different helminth parasitic species were encountered as Toxocara cati (40%), Toxascaris leonina (16.67%), and Ancylostoma tubaeforme (10%) belonging to nematodes and a species of cestode: Hymenolepis diminuta (6.67%). Nematode infection (66.67%) was found to be comparatively more common than cestode infection (6.67%). Statistically, the relationship between the cestode and nematode parasite is significant (x2 = 0.232, p&gt;0.05). The high incidence of parasitism of cats was due to the relative influence of behaviour and a contaminated environment since these cats lived in the same environment as other domestic animals. The study recommended that studies on all kinds of gastrointestinal parasites, including protozoan parasites, would be better to get more knowledge about parasites and their risk of transmission.

A240 THE PROTECTIVE EFFECT OF HYMENOLEPIS DIMINUTA INFECTION IN EXPERIMENTAL COLITIS CAN BE INDEPENDENT OF IL-4RΑ SIGNALING

Abstract Background Helminth parasites are potent inducers of Th2 immunity, characterized by the production of IL-4, IL-5, IL-13 and IL-10, and mobilization of regulatory cells. This orchestrated immune response establishes an immunomodulatory and/or immunosuppressive environment that may be protective against colitis and other inflammatory diseases. Earlier studies reveal that infection with the tapeworm parasite Hymenolepis diminuta ameliorates chemical-induced colitis in immunocompetent mice, and highlighted participation of the anti-inflammatory cytokine IL-10 in the mechanisms of protection. Moreover, the IL-4ra/STAT6 signaling pathway plays a pivotal role in promoting the Th2 immune response that is crucial for parasite expulsion: IL-4ra KO mice cannot expel the worm. However, the need for activation of IL-4rasignaling in the suppression of colitis by H. diminuta infection is unknown. Aims To determine if the inhibition of DNBS-induced colitis evoked by infection with H. diminuta requires IL-4ra signaling. Methods IL-4ra KO mice (n=4-8/group) were orally infected with 5 viable cysticercoids of H. diminuta and 8 days post-infection (dpi) were treated with 2.5 mg of dinitrobenzene sulfonic acid (DNBS). Subsequently, mice were assessed 72h post-DNBS. Disease was assessed by macroscopic disease activity score, colon length, weight loss, MPO activity of the colon, and leucocyte profile by blood count. Production of IL-10 by concanavalin-A (con-A; 48h)-stimulated splenocytes was measured by ELISA. Results An increase in blood eosinophilia in H. diminuta infected mice indicated a successful infection. DNBS treatment induced acute colitis in IL-4ra KO mice, and surprisingly prior infection with H. diminuta resulted in significantly less severe colitis, as evidenced by reduction in macroscopic disease activity score, prevention of weight loss, reduced MPO colon levels and maintenance of regular colon length. However, splenocytes from H. diminuta-infected IL-4ra KO mice did not show increased IL-10 production evoked by con-A compared to cells from non-infected mice. Conclusions These results indicate that the protection against DNBS-induced colitis by prior infection with H. diminuta can occur in the absence of IL-4ra signalling. This suggests redundancy in the anti-colitic effect of infection with this helminth parasite, such that absence of IL4ra is compensated for via another, yet to be determined, mechanism. We speculate that this may be via participation of type 2 innate lymphoid cell activity, mobilization of regulatory T cells or innate immunity: all possibilities that need to be rigorously tested. Funding Agencies CIHRBeverly Phillips Rising Star and Cumming School of Medicine (U. Calgary) Fellowships