Eurytrema coelomaticum infection: correlation between parasite burden and impairment of pancreatic exocrine enzyme secretion

ABSTRACT: Eurytrema coelomaticum is a trematode reported in the pancreatic ducts of ruminants. It is conjectured that may cause disorders in the pancreas, as well as digestive and metabolic processes dependent on them. This study, determined if there is an impairment of exocrine pancreatic function, and correlated it with parasite burden. Pancreas, blood, and fecal samples were collected from 119 bovines at a abattoir. Stool samples were subjected to the gelatin and x-ray film digestion tests (to detect the presence of trypsin in feces). Using blood samples, the following biochemical tests were performed: amylase, lipase, glucose, fructosamine, cholesterol, triglycerides, total protein, albumin, and globulins. Analyses were correlated with pancreatic parasite burden. Cattle with a high parasitic load presented higher incidence of negative tests in both gelatin digestion and x-ray film digestion tests (P < 0.001) when compared to non-parasitized animals and those with a low parasitic load. Changes in those tests only occurred if the parasitemia was moderate or severe. The activity of the amylase and lipase enzymes was significantly higher in animals with low parasitemia (P < 0.05), compared to non-parasitized animals and with a high parasitic burden. In this study, in cases of high parasitemia, negative results were observed in both gelatin and x-ray film in the feces digestion tests. However, the low infection of E. coelomaticum, higher levels of serum amylase and lipase that also indicated loss of pancreatic exocrine functions were reported.

Pathological findings in bycaught harbour porpoises (Phocoena phocoena) from the coast of Northern Norway

Due to little prior knowledge, the present study aims to investigate the health status of bycaught harbour porpoises from the northernmost Arctic Norwegian coastline. Gross, histopathological and parasitological investigations were conducted on 61 harbour porpoises (Phocoena phocoena phocoena) accidentally captured in fishing gear from February to April 2017 along the coast of Northern Norway. Most animals displayed a good nutritional status, none were emaciated. Pulmonary nematodiasis (Pseudalius inflexus, Halocercus invaginatus and Torynurus convolutus) was found in 77% and associated with severe bronchopneumonia in 33% of the animals. The majority (92%) had parasites in the stomach and intestine (Anisakis simplex sensu stricto (s. s.), Pholeter gastrophilus, Diphyllobothrium stemmacephalum, Hysterothylacium aduncum and Pseudoterranova decipiens s. s.). The prevalence of gastric nematodiasis was 69%. In the 1st stomach compartment A. simplex s. s. was found in 30% of the animals, causing severe chronic ulcerative gastritis in 23%. Campula oblonga infected the liver and pancreas of 90% and 10% of the animals, respectively, causing severe cholangitis/pericholangitis/hepatitis in 67% and moderate pancreatitis in 10% of the animals. Mesenteric and pulmonary lymphadenitis was detected in 82% and 7% of the animals, respectively. In conclusion, the major pathological findings in the investigated Arctic porpoises were parasitoses in multiple organs with associated severe lesions, particularly in the lung, liver and stomach. The animals were generally well nourished and most showed freshly ingested prey in their stomachs. The present study indicates that the harbour porpoises were able to tolerate the detected parasitic burden and associated lesions without significant health problems.

Detrimental role of IL-33/ST2 pathway sustaining a chronic eosinophil-dependent Th2 inflammatory response, tissue damage and parasite burden during Toxocara canis infection in mice

Toxocariasis is a neglected disease that affects people around the world. Humans become infected by accidental ingestion of eggs containing Toxocara canis infective larvae, which upon reaching the intestine, hatch, penetrate the mucosa and migrate to various tissues such as liver, lungs and brain. Studies have indicated that Th2 response is the main immune defense mechanism against toxocariasis, however, there are still few studies related to this response, mainly the IL-33/ST2 pathway. Some studies have reported an increase in IL-33 during helminth infections, including T. canis. By binding to its ST2 receptor, IL-33 stimulating the Th2 polarized immune cell and cytokine responses. Thus, we aimed to investigate the role of the IL-33/ST2 pathway in the context of T. canis larval migration and the immunological and pathophysiological aspects of the infection in the liver, lungs and brain from Wild-Type (WT) BALB/c background and genetically deficient mice for the ST2 receptor (ST2-/-). The most important findings revealed that the IL-33/ST2 pathway is involved in eosinophilia, hepatic and cerebral parasitic burden, and induces the formation of granulomas related to tissue damage and pulmonary dysfunction. However, ST2-/- mice, the immune response was skewed to Th1/Th17 type than Th2, that enhanced the control of parasite burden related to IgG2a levels, tissue macrophages infiltration and reduced lung dysfunction. Collectively, our results demonstrate that the Th2 immune response triggered by IL-33/ST2 pathway mediates susceptibility to T. canis, related to parasitic burden, eosinophilia and granuloma formation in which consequently contributes to tissue inflammation and injury.

Correlation of the Gastrointestinal Parasitism with the Phytominerals in the Grazing Sheep (Ovis aries)

Trace elements play an important role to boost the immunity and fight against parasitic infections. Concentration of trace elements like Copper (Cu), Cobalt (Co), Manganese (Mn) and Zinc (Zn) were determined in soil, forages and sera of sheep. An associative analysis was also made between the burden of Gastrointestinal (GI) parasites and concentrations of trace elements of sheep sera. For this, 384 faecal and blood samples of sheep, an appropriate number of forages and soil samples were collected. The faecal samples were subjected to determine the species and burden of GI parasites. The sera, plant and soil samples were subjected to pre-treatment (digestion) required for the determination of trace elements. The overall prevalence of GI parasites was 32.81% and the most prevalent species were Haemonchus (H.) contortus followed in order by Eimeria spp., Strongyloides spp., Trichostrongylus spp. and Fasciola spp. Variables like age, sex, breed and tehsils of Silakot district showed an insignificant association with GI parasitic burden. Trace elements concentration of forages showed a significant (P < 0.05) variation while trace elements concentration of soil showed an insignificant (P > 0.05) variation. In serum, Zn concentration showed significant (P < 0.05) results among all the tehsils of study district. Mean concentrations of Mn and Cu in serum were found inversely proportional to the mean egg count per gram of sheep faeces in tehsil Pasroor of the Sialkot district. Forages containing high concentrations of Mn and Cu can be used effectively against GI parasites. © 2021 Friends Science Publishers

Determination of parasitic burden in the brain tissue of infected mice in acute toxoplasmosis after treatment by fluconazole combined with sulfadiazine and pyrimethamine

Background/aims One of the opportunistic pathogens which cause serious problems in the human immune system is Toxoplasma gondii, with toxoplasma encephalitis (TE) seen in patients affected by it. The treatment of these patients is limited, and if not treated on time, death will be possible. Methods In this study, the effects of the treatment with different doses of fluconazole (FLZ) in combination with the current treatment of acute toxoplasmosis on reducing the mortality rate and the parasitic load in the murine model in vivo were studied. The mice were treated with different doses of fluconazole alone, sulfadiazine, and pyrimethamine plus fluconazole. A day after the end of the treatment and 1 day before death, the mice’s brains were collected, and after DNA extraction and molecular tests, the parasite burden was detected. Results This study showed that a 10-day treatment with 20 mg/kg of fluconazole combined with sulfadiazine and pyrimethamine 1.40 mg/kg per day affected acute toxoplasmosis and reduced the parasitic load significantly in brain tissues and also increased the survival rate of all mice in this group until the last day of the study, in contrast to other treatment groups. These results also indicate the positive effects of combined therapy on Toxoplasma gondii and the prevention of relapse. Conclusions Reducing the parasitic burden and increasing the survival rate were more effective against acute toxoplasmosis in the combined treatment of different doses of fluconazole with current treatments than current treatments without fluconazole. In other words, combination therapy with fluconazole plus pyrimethamine reduced the parasitic burden in the brain significantly, so it could be a replacement therapy in patients with intolerance sulfadiazine.

Seasonal histopathological alterations caused by Bothriocephalus acheilognathi in Schizothorax niger of Kashmir valley

Liver and intestines affected by an cestode parasite viz., Bothriocephalus acheilognathi along with their host (Schizothorax niger) were collected randomly. Bothriocephalus acheilognathi causes damage to the intestinal tissues and induce complex host response; the affected fish were anemic and emaciated. The viscera were dark red on opening the abdomen. The intestinal contents showed lot of mucous and contained dark contents. The mucosal wall was red in colour and revealed necrotic surface. The histopathological changes were varied in severity with the season and parasitic burden. Intestinal infection of Bothriocephalus with Adenoscolex was usually seen together. Severe enteritis with heavy infilitration of inflammmtory cells and fibroblasts seen in lamina propia. Liver cells showed severe degenerative changes.

Stress hormone level and the welfare of captive European bison (Bison bonasus): the effects of visitor pressure and the social structure of herds

Background Captive European bison (Bison bonasus) play an active role in conservation measures for this species; this includes education, which may conflict with these animals’ welfare. The effect of the presence of visitors on the welfare of captive animals can be negative, positive or neutral. However, the response of a given species to visitors is difficult to predict, since even closely related species display varying levels of tolerance to captivity. The aim of the study was to compare immunoreactive fecal cortisol levels (regarded as an indicator of the level of physiological stress) in groups of captive European bison that differed in terms of their social structure and the level of visitor pressure. The second aim was to determine if there was a correlation between intestinal parasitic burden and immunoreactive fecal cortisol levels. Results Immunoreactive fecal cortisol levels were not influenced by sex or age. However, study site and the interaction between study site and visitor pressure were statistically significant. European bison in one enclosure presented higher levels of immunoreactive fecal cortisol on weekdays than at weekends. In the other two study sites, the levels did not differ between weekdays and weekends. No correlation was found between parasitological infestation and immunoreactive fecal cortisol levels. Conclusions Measurement of fecal cortisol metabolites could be a valuable method for further research into the welfare of European bison in captivity. More subtle factors such as individual animal characteristics, feeding systems, and the arrangement of enclosures can be of great importance in terms of the effect of visitors on animals. The results of this study can be used in guidelines for the management of European bison populations.

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

The aim of this study was to investigate the correlation between infection by Dicrocoelium dendriticum (class Trematoda) and the animal host response in terms of macroscopic lesions, the immunopathological response, and histological changes in the livers of naturally infected sheep. Twenty-four sheep were selected on the basis of positive D. dendriticum fecal egg counts (FECs). Gross and histological injuries were scored. A positive significant association was observed between the number of adult worms recovered from the liver, FEC, macroscopic lesions, fibrosis, and bile duct hyperplasia. A significant negative association was observed among these variables and the degree of leukocyte infiltration. In addition, immunophenotyping of the inflammatory cells was carried out using primary antibodies against T cell epitopes (CD3+, CD4+, and CD8+), B cell epitopes (CD79α), and the ionized calcium-binding adapter molecule 1 (IBA-1) antigen. Independently of the severity of the D. dendriticum infection, the predominant cell population was CD3-positive and associated with lesser numbers of CD79α- and Iba-I-positive cells. An increase in Iba-1-positive cells was observed in the livers of animals with a high worm burden. Our results provide a reference basis to better understand the local immune response in sheep naturally infected by D. dendriticum in relation to the FEC and parasitic burden.

Vaccines in Congenital Toxoplasmosis: Advances and Perspectives

Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human vaccines available to prevent this infection. Most vaccination studies against Toxoplasma gondii infection used animal models in which the infection was established by exogenous inoculation. Here, we review recent research on potential T. gondii vaccines using animal models in which infection was congenitally established. Endeavors in this field have so far revealed that live or subunit vaccines previously found to confer protection against extrinsically established infections can also protect, at least partially, from vertically transmitted infection. Nevertheless, there is no consensus on the more adequate immune response to protect the host and the fetus in congenital infection. Most of the vaccination studies rely on the assessment of maternal systemic immune responses, quantification of parasitic loads in the fetuses, and survival indexes and/or brain parasitic burden in the neonates. More research must be carried out not only to explore new vaccines but also to further study the nature of the elicited immune protection at the maternal-fetal interface. Particularly, the cellular and molecular effector mechanisms at the maternal-fetal interface induced by immunization remain poorly characterized. Deeper knowledge on the immune response at this specific location will certainly help to refine the vaccine-induced immunity and, consequently, to provide the most effective and safest protection against T. gondii vertical infection.

High Burden of Gastrointestinal Helminth Parasites in Catfishes: Clarias gariepinus and Heteropneustes fossilis

Objective: Catfishes harbour a greater variety and occurrence of larval helminth parasites because they are exposed to more infective helminth larvae in their diet due to their predatory habit which makes them more susceptible to higher parasitic burden. This study was conducted at department of zoology in Post Graduate Campus, Biratnagar, Nepal to determine the prevalence of helminth parasites in the gastrointestinal tract of two species of catfishes i.e Clarias gariepinus and Heteropneustes fossilis collected from the different water resources of Biratnagar, Eastern Nepal.Results: Out of 280 fish examination, 264 (94.28%) fishes were found to be infected with helminths parasites. Clarias gariepinus infection rate was 84.0% with three species of parasites, one each of nematode i.e. Procamallanus laevionchus, cestode i.e. Proteocephalus species, and trematode i.e. Allocreadium species. Heteropneustes fossilis have prevalence rate of 100% with five species of helminth parasites i.e. two nematode species namely Procamallanus heteropneustes and Eustrongyloides species, one cestode namely Lytocestus indicus, one trematode i.e. Phyllodystomum folium and an acanthocephalan i.e. Pomphorhynchus species were detected.