Parasitological Studies Research Articles

Veterinary and sanitary examination of salted pacific herring with Anisakidosis

Canning fish with table salt is one of the predominant processing methods that helps protect the product from decomposition by microorganisms and is used as disinfection for some invasive diseases. But the violation of manufacturing technologies and the use of stale fish as raw materials contributes to the development of defects and the preservation of the viability of parasites, which can pose a danger to human health.Anisakidosis is a helminthiasis caused by nematodes from the genus Anisakis simplex, localized in the muscle tissue and serous membranes of marine fish. This pathogen leads to intestinal invasions in many species of mammals, including humans.The purpose of our study was to conduct a parasitological study of samples of Atlantic herring (Clupea harengus) undivided salted of different brands.This article highlights the study of Atlantic herring of different brands sold in the retail chain of St. Petersburg. An external and internal examination of herring, a compressor study of muscle tissue and a study using the method of parallel muscle incisions were carried out. Among the studied samples, according to the results of the parasitological study, trademarks I and II account for 4 infected herring out of 10 (40%), and among the samples of trademark III, 7 out of 10 samples were affected by nematodes of the genus Anisakis simplex (70%).

Trichurid nematodes from South American Camelid: an approach to native assemblages through the parasitology of archaeological sites.

To gain insights into the trichurid diversity in pre-Hispanic remains of South American camelids (SACs), as well as into modern SAC populations, a bibliographic search was carried out to find parasitological studies. Results showed that a total of 17 studies were performed at archaeological and paleontological sites, in which a total of 213 samples were examined. The sample set was used as the unit of analysis, and 83% of 52 pre-Hispanic sample sets were positive for parasites. Parasitological studies confirmed the pre-Hispanic presence of diverse trichurids: two Trichuris species and capillariid eggs with morphological differences that allowed them to be assigned to three different species. Currently, the richness of the native trichurid assemblages in SACs has been extended by the inclusion of two species (Trichuris sp. 2 and Capillariinae gen. sp. 1). Modern T. tenuis Chandler, 1930, considered SAC-specific, would have invaded SAC populations during the European colonization. The estimate of regional and temporal trichurid prevalence and paleoecological information allowed us to propose a possible origin for some of them. Although the present analysis is exploratory, it should stimulate future studies about the biogeographic history of SAC helminths, provide relevant information to improve descriptions of the Holocene ecology, and identify threatened helminths.

New approaches to the study of dominant nosological units - the main element of the control of the epizootic process

In a comparative aspect and dynamics in the conditions of urbanized territories, the structure of invasive pathology and the effectiveness of anti-invasive measures were studied. It was established that the epizootic situation is controlled by parasitological, microscopic and hematological studies for 12 invasions. It was determined that from the period from 2020 to 2022, there is a negative trend in the defeat of farm animals and unproductive domestic animals with invasive diseases (from 25% in 2020 to 0.57% in 2022). At the same time, nematodes play a leading role in the invasive pathology of animals - from 60.5% of those affected in small cattle to 0.6% in dogs. In our opinion, the negative dynamics is associated with the optimization of the system of anti-epizootic measures in a metropolis, aimed at the source of the pathogen, the mechanism of its transmission and susceptible animals. It was stipulated that in order to control and determine the effectiveness of the implementation of an optimized scientifically based system of antiparasitic measures, continuous study and assessment of the epizootic situation among cattle are required; laboratory screening of animals and habitat.

Evaluation of the therapeutic effect of Olibanum extract against enteric and intramuscular phases of trichinosis in experimentally infected mice.

Trichinosis is a global food-borne zoonotic disease. Most drugs used in its treatment have low bioavailability and reduced activity against larvae. Therefore, there is an urgent need for safe and effective medications. This study aimed to investigate the in vivo anti-parasitic and anti-inflammatory efficacy of olibanum (OL) extract, alone or combined with albendazole (ABZ) during both intestinal and muscular phases of trichinosis. Male Swiss albino mice (n = 130) were allocated to seven groups, with 20 mice in each group except for the negative control group (10 mice): negative control (GI), positive control (GII), OL25- treated (GIII), OL50- treated (GIV), ABZ50- treated (GV), OL25 + ABZ25 (GVI), and OL50 + ABZ25 (GVII). For intestinal and muscular phase analysis, each group was divided into two subgroups based on euthanizing day (6 and 35 days post-infection). The drug's efficacy was evaluated through parasitological, biochemical, histopathological, and immunohistochemical studies. OL extract at both concentrations (25 mg/kg/d, 50 mg/kg/d) significantly reduced adult (53.7% and 68.1%, respectively) and larval counts (57.3% and 78.8%, respectively). It improved the histopathological changes in intestine and muscle. The expression of CD8+ T cells and the serum level of IL-10 increased significantly during both intestinal and muscular phases (P < 0.05) in OL50 treated mice. Additionally, OL decreased abnormal levels of liver enzymes (ALT & AST). Its effects were dose-dependent in both adult and larval stages. In conclusion, OL exhibits promising in vivo activity against both stages of Trichinella spiralis infection, particularly at the intramuscular phase. It can be safe as an alternative treatment for trichinosis.

Antihelminthic and antiangiogenic effects of zinc oxide nanoparticles on intestinal and muscular phases of trichinellosis.

Trichinellosis is a worldwide zoonotic disease affecting a wide range of mammals, including humans. It has intestinal and muscular phases. The current work was done to experimentally evaluate the efficacy of zinc oxide nanoparticles (ZnO NPs) and their combination with albendazole on intestinal and muscular stages of Trichinella spiralis (T. spiralis) infection. We had five main groups of mice: Group 1, non-infected control; Group 2, infected control; Group 3, infected and treated with albendazole; Group 4, infected and treated with ZnO NPs; and Group 5, infected and treated with albendazole and ZnO NPs. Each group was divided into two subgroups (A for the intestinal phase and B for the muscular phase). Drug effects were evaluated by parasitological, histopathological, and biochemical studies, including oxidant/antioxidant analysis and vascular endothelial growth factor (VEGF) gene expression in muscle tissue by quantitative real-time PCR. ZnO NPs resulted in a significant reduction of both intestinal and muscular phases of T. spiralis. Their combination with albendazole resulted in the complete eradication of adult worms and the maximum reduction of larval deposition in muscle tissue. Additionally, the treatment showed improvement in T. spiralis-induced pathological changes and oxidative stress status. Moreover, a significant decrease in VEGF gene expression was detected in the treated groups when compared with the infected control. In conclusion, ZnO NPs presented an antihelminthic effect against both adult and larval stages of T. spiralis. In addition, it enhanced antioxidant status and suppressed angiogenesis in muscle.

Morphological and molecular characterization of Trichuris muris (Nematoda: Trichuridae): studies from two commensal rodent species.

In this paper we re-describe Trichuris muris based on morphological data following isolation from two commensal rodent species, Mus musculus from Mexico and Rattus rattus from Argentina. Furthermore, we provide a molecular characterization based on mitochondrial (cytochrome c oxidase subunit 1 mitochondrial gene) and nuclear (internal transcribed spacer 2 region) markers in order to support the taxonomic identification of the studied specimens of T. muris from M. musculus. We distinguished T. muris from 29 species of Trichuris found in American rodents based on morphological and biometrical features, such as the presence of a spicular tube, length of spicule, size of proximal and distal cloacal tube and non-protrusive vulva. We suggest that spicular tube patterns can be used to classify Trichuris species in three groups. Considering that the diagnosis among the species of this genus is mainly based on morphometry, this proposal represents a relevant contribution. We provide molecular studies on two markers, making this the first contribution for T. muris in the Americas. This study makes an important contribution to the integrative taxonomy of cosmopolitan nematode species, and its correct determination from the parasitological study of commensal rodents.

Wintering Rooks, Corvus frugilegus (Aves, Corvidae) and Their Helminths in Poltava and Kyiv, Ukraine

Observations of wintering rook populations were carried out from late October till early March in 2020–2021 and 2021–2022 in the cities of Poltava and Kyiv. In Poltava, rooks made up 95 % of the approximately 50,000 wintering corvids, and in Kyiv, more than 93% of the approximately 90,000 corvids. Up to 10 % of the rooks observed in Poltava were juveniles; no juvenile rooks were observed in Kyiv. Forty-six dead rooks (24 in Poltava and 22 in Kiev) collected on the ground at roosting sites were used for parasitological studies. We found 13 helminth species in the two samples of rooks, 10 species were recorded in each sample. In both samples, nematodes predominated by their infection prevalence and abundance. At the levels of helminth populations and infracommunities, the differences between the two samples were mostly influenced by the infection parameters of the nematodes Acuaria anthuris, Baruscapillaria resectum, Diplotriaena tricuspis, Eucoleus frugilegi, Microtetrameres spp., and the cestode Spiniglans affinis. In the helminth component community from Poltava, the evenness and diversity indices were comparatively higher than in the component community from Kyiv; Microtetrameres spp. was the predominat taxon. In the component community from Kyiv, E. frugilegi predominated by its infection prevalence and abundance.

Prevalence of Intestinal Parasites and its Predisposing Factors among Patients Sent for Stool Examination at Ambo General Hospital, Oromiya Region, Ethiopia

Back ground: Intestinal parasitic infections are the most common infection in the world. In Ethiopia there is a high prevalence of intestinal parasites due to lack of personal hygiene and poor environmental conditions. Objective: The aim of the study was to assess the prevalence of intestinal parasites and predisposing factors among patients who sent for stool examination at Ambo general hospital Ambo Town, West Shewa zone. Methodology: A cross- sectional parasitological study was conducted August 22, 2021- August 31, 2021 G.C to determine the prevalence of intestinal parasites and its portion formula was used to determine a total sample size and convenient sampling technique was used. After ethical approval taken, patients data was collected by face-to face interviewing and recording method. Stool samples was examined by using direct saline and formal ether concentration techniques. Collected data was analyzed manually, checked and edited to determine the related risk factors of the intestinal parasites. Result and Conclusion: There was high prevalence of intestinal parasitic infection in the study in which 63.1% of them were found to be positive for at least single intestinal parasite. Total of seven intestinal parasites were identified. From the identified species G.lambilia was the most common 110(52.9%) followed by E.histolytica 42(20.2%), A.lambricoids 16(7.7%), Hook worm 12(5.8%), Tina species 10(4.8%), T.trichuria 10(4.8%) and S.mansoni 10(4.8%). Recommendations: Educate the patients and inform the concerned bodies about the risk factors and prevention. This finding from the study could be used as base line data and further investigation should be done to know the problem of intestinal parasitism more in the area by the others.

ЗАРАЖЕННОСТЬ КАРПОВЫХ РЫБ ЛИЧИНКАМИ ПАТОГЕННЫХ ДЛЯ ЧЕЛОВЕКА ГЕЛЬМИНТОВ И БАКТЕРИЯМИ В НИЖНЕЙ ЗОНЕ ДЕЛЬТЫ РЕКИ ВОЛГИ В СОВРЕМЕННЫЙ ПЕРИОД

Recreational and artisanal fishing is very widespread in the Astrakhan Region; its primary targets are cyprinids, which are susceptible to epedemiological threats. Food products derived from the biological resources harvested during such fishing are not subjected to the processing in specialized facilities, and therefore, safety of the final product for its consumer cannot be ensured. In this region, the diseases, the agents of which are transmitted through fish and the products of its processing, are annually recorded among the population. Sanitary and parasitological control is one of the components in the set of measures for the prevention of these diseases. This work was aimed at evaluation of the infection level in some species of commercially valuable cyprinids in the Lower Volga River Delta with bacteria and larvae of pathogenic helminths capable of causing the development of diseases in humans. An incomplete helminthological survey of Caspian roach, common bream, white bream, crucian carp and rudd, as well as microbiological examination of their muscle tissue have been carried out in accordance with the requirements of the regulatory documents currently in force with application of methods described in State Standards. Larvae belonging to four species of human-pathogenic parasites have been recorded in the parasitic fauna of the Caspian roach, rudd, and white bream. Common bream was infected by larvae belonging to two species of such helminths. The identified larvae of pathogenic trematodes and nematodes were viable. The level of bacterial contamination of fish muscle tissues did not exceed the standard-prescribed limit, and the sanitary indicator microorganisms were absent. The results of the parasitological study indicated the need for mandatory disinfection of cyprinid fish from larvae of pathogenic helminths.

Gastrointestinal parasite assemblages from the wild rodent capybara (Hydrochoerus hydrochaeris) inhabiting a natural protected area from Argentina

Abstract Knowledge about parasitic diseases of wildlife will help us to understand the dynamics of parasites and their effects on host populations. The capybara (Hydrochoerus hydrochaeris) is the largest living rodent in the world, and its distribution is associated with the presence of tropical and subtropical wetlands in South America. The Los Padres Lake Integral Reserve (LPLIR) is an important conservation zone in the pampean region of Argentina. One of the emblematic species found within the reserve is the capybara. The objective of this study was to determine the gastrointestinal parasites present in wild capybaras of the LPLIR and to compare different coprological methodologies. Free-ranging capybara fresh feces from 57 individuals were randomly collected from the area of LPLIR in the summer of 2022. Three different techniques were applied: spontaneous sedimentation technique (SS), INTA modified McMaster technique (MM), and Mini-FLOTAC (MF) technique. Fifty-six samples from all samples analysed (56/57, 98%) were found to be positive for gastrointestinal parasites. Two species of Strongylida, Protozoophaga obesa, Echinocoleus hydrochaeris, one unidentified nematode, one unidentified spirurid, and at least two morphotypes of Eimeria spp. oocysts were recorded. There were found significant differences in the proportion of positive samples and in richness by technique, but no significant differences were found in parasite counting. In conclusion, the choice of methodology depends on the specific objectives of the study. This is the first parasitological study of capybaras from the LPLIR and represents an exploration of parasite communities present in these wild rodents at their southernmost distribution.

Влияние экологической ситуации бассейна реки Вилюй Якутии на показатели качества рыбных ресурсов

The article considers the quality indicators of fish resources extracted in the basin of the Vilyu river of the Nyurbinsky district of Yakutia, which is a zone of industrial development of a diamond deposit. The influence of the environment on the safety of various species of fish that make up the fauna of the Vilyu River near the village of Nyurba was studied; organoleptic, physico-chemical, microbiological, parasitological studies of frozen fish specimens were carried out: pike, tugun, peled. According to the results of veterinary and sanitary studies, it was found that bacteria of the Escherichia coli group were found in the tugun fish sample during microbiological examination, which indicates repeated defrosting of fish; the remaining fish samples (pike, pelage) were benign and met the requirements of regulatory documentation. Laboratory analyses conducted on organoleptic, physico-chemical, microbiological indicators, parasitological studies indicate that pollution of the Vilyu River as a result of industrial waste dumping, which occurred in 2017-2018, did not affect the quality of fish fauna. Timely financing and implementation of measures within the framework of the government program "Development of water supply systems of the Vilyui group of uluses for 2019-2024" stabilized the environmental situation in the Vilyui group of uluses. Keywords: ECOLOGY, FISH RESOURCES, EXPERTISE, SAFETY, QUALITY

The Infection Rate of Bird-Feeding Ixodes ricinus Ticks with Borrelia garinii and B. valaisiana Varies with Host Haemosporidian Infection Status.

Birds are known to maintain and spread human pathogenic borreliae, but they are common hosts of diverse parasite communities, notably haemosporidians. Only a few studies examined whether tick infestation and/or Borrelia prevalences vary with hosts' haemosporidian infection status. Here, we study whether Ixodes ricinus infestation rates and Borrelia infection rates in bird-feeding ticks vary according to haemosporidian infection status in a community of free-living avian tick hosts. Birds of six avian species harbored the majority of ticks. Both the tick infestation prevalence and the intensity peaked during spring and summer, but while bird-feeding nymphs prevailed in spring, bird-feeding larvae dominated in summer. Almost half of the bird-feeding ticks were found to be positive for B. burgdorferi s.l. Although the majority of infections involved bird-associated B. garinii and B. valaisiana, B. garinii appears to be the dominant Borrelia strain circulating in locally breeding avian species. We detected a negative link between the hosts' haemosporidian infection status and the Borrelia infection rate of bird-feeding ticks, but the association was dependent on the host's age. Our results on tick infestation intensity support the idea that more immunologically vulnerable hosts harbor more ticks but suggest that different mechanisms may be responsible for tick infestation rates among immunologically naïve and experienced avian hosts. The results on Borrelia infection rates in bird-feeding ticks are consistent with studies revealing that intracellular parasites, such as haemosporidians, can benefit from the host immune system prioritizing immune responses against extracellular parasites at the expense of immune responses against intracellular parasites. The findings of our study urge for a more robust design of parasitological studies to understand the ecology of interactions among hosts and their parasites.

COMPARATIVE ASSESSMENT OF COMPLEX DRUGS BASED ON MOXIDECTIN AND PRAZIQUANTEL FOR DOG ENDOPARASITIC INVASIONS

The article presents data on the effectiveness of the new domestic complex antiparasitic drug «Moxistop for dogs» in comparison with the reference drug «Vormazol for dogs spot-on» that used for the treatment and prevention of endoparasitic infestations in dogs of different breeds, ages and sexes.&#x0D; According to the results of parasitological studies, the animals of experimental and control groups were found to be spontaneously infected with endoparasites, the causative agents of nematodes: Toxocara canis with an intensity of invasion (II) from 210 to 250 eggs in one gram of feces, Ancylostoma caninum – from 52 to 80, Trichuris vulpis – from 58 to 85, respectively, and the cestode pathogen Dipylidium caninum – from 20 to 46 cocoons in one gram of feces. Nematodes and cestodosis in dogs were manifested clinically by: deterioration of appetite, depression, paleness of mucous membranes, and in some animals, vomiting and mild diarrhea (unformed feces).&#x0D; Before 7th day and during next 7th-14th day after deworming, helminthocoprological studies were carried out with the establishment of indices of parasitological damage and determination of the extensive effectiveness and intensive effectiveness of the drugs.&#x0D; Based on the obtained results, it was found that for a spontaneous toxocarosis infestation of dogs on the 7th and 14th day after deworming, the intensity effectiveness (IE) of the experimental drug «Moxistop for dogs» was 96.0 and 98.3%, and the intensity effectiveness of the reference drug «Vormazol for dogs spot-on» – 92.2 and 95.1%, respectively. At the same time, the extensive effectiveness (EE) of both drugs for 7 and 14 days after deworming was 85.7%.&#x0D; Helminthological studies showed that for spontaneous hookworm infestation in dogs on 7th and 14th days after the use of the experimental drug and the reference drug in the recommended doses, the intensive and extensive effectiveness of the drugs was 100% in the experimental and control groups of animals.&#x0D; In the case of spontaneous trichuria infestation, it was found that on the 7th and 14th day after deworming, the intensity of the experimental drug was 91.7 and 93.1%, and the intensity of the reference drug was 92.8 and 94.2%, respectively.&#x0D; At the same time, it was found that for spontaneous dipilidiosis infestation of dogs, the intensity of the experimental drug «Moxistop for dogs» on the 7th day after deworming was 95.1% and on the 14th day – 96.9%, and the intensity of the reference drug «Vormazol for dogs spot-on» on the 7th and 14th day after deworming was 92.9 and 95.8%, respectively.&#x0D; Field tests have shown that the research drugs are convenient to use, well tolerated by animals regardless of age, body weight and breed, and do not have a toxic effect on the animal's body when they are used once by the spot-on method in the manufacturer's recommended doses.

The Prevalence and Control of Lungworms of Pastoral Ruminants in Iran.

Lungworms of the genera Dictyocaulus, Muellerius, Protostrongylus, and Cystocaulus are common helminths of domestic and wild ruminants with substantial veterinary and economic importance. Several studies have assessed the presence and prevalence of lungworm infections in ruminants in Iran. This report compiles the available scientific information about the occurrence of lungworms in domestic and wild ruminants in Iran between 1931 and June 2022 to give an insight into their epidemiology, and where possible to describe drug treatment efficacy. For this purpose, national and international scientific databases were searched. Overall, 54 publications comprising 33 articles in peer-reviewed journals, 8 conference papers, and 13 dissertations were evaluated regarding prevalence data; and an additional 4 peer-reviewed articles were evaluated regarding drug efficacy. Seven species of lungworms, namely Dictyocaulus filaria, Dictyocaulus viviparus, Dictyocaulus eckerti, Protostrongylus rufescens, Protostrongylus raillietti, Muellerius capillaris, and Cystocaulus ocreatus have been recorded from different ruminant hosts in Iran. Thirty-three studies conducted on small ruminant (sheep and goat) lungworms reported prevalences of lungworm infection of 11.6%, 45.81% and 66.29% using abattoir meat inspection, Baermann technique and fecal flotation, respectively. Eight studies conducted on large ruminants (cattle and water buffalo) reported prevalences of infection of 14.83%, 13.98% and 5% using abattoir meat inspection, the Baermann technique and fecal flotation, respectively. The prevalence of infection in wild ruminants was variable across examined species; 38% in urial, 37% in wild goats, 5% in goitered gazelles and 67% in red deer, in addition to a single case report in roe deer. There are few contemporary studies assessing the efficacy of currently available broad-spectrum anthelmintic compounds against lungworms in Iran. The high prevalence of multiple lungworm species in Iran, combined with a lack of information about drug efficacy, supports the need to improve the understanding of these important nematode parasites and inform the development of sustainable control strategies. The aim of this review and meta-analysis is to provide a baseline for future conventional parasitology and next generation molecular epidemiological studies of lungworm infection in pastoral ruminants in Iran.

Teachers as multipliers of knowledge about schistosomiasis: a possible approach for health education programmes

BackgroundIn the past decade, Brazil has significantly reduced the prevalence of schistosomiasis through a combined effort of early treatment of infected people, expansion of basic sanitation infrastructure and educational measures. Despite these efforts, in some areas, prevalence of schistosomiasis exceeds 20% of the school population, who lack knowledge of the risks of the disease. Action can be taken in schools to empower this population about their health condition. This paper describes the role of the teacher as a multiplier of knowledge about schistosomiasis and proposes two different approaches to training these teachers.MethodsThis study used mixed methods to evaluate training of teachers and educational intervention with those teachers’ pupils. Two training courses, each with 40 h of face-to-face activity, were offered to 19 teachers, using two different but complementary approaches, based on theoretical references and specific educational strategies: Critical Pedagogical Approach (Training Course I, held in 2013) and Creative Play Approach (Training Course II, held in 2014).The courses included classroom activities, laboratory and field work. After the training, the teachers conducted activities on schistosomiasis with their pupils. These activities involved constructing educational materials and cultural productions. The pupils’ knowledge about the disease was evaluated before the activities and 12 months later. The teachers’ acceptance and perceptions were assessed through structured interviews and subsequent thematic analysis. The Shistosoma mansoni infection status of teachers and their students was also assessed using the Kato Katz stool test.ResultsThe parasitological study showed 31.6% of the teachers and 21.4% of the pupils to be positive for S. mansoni. The teachers’ knowledge of important aspects of schistosomiasis transmission and prevention was fragmented and incorrect prior to the training. The teachers’ knowledge changed significantly after the training and they were strongly accepting of the pedagogical methods used during the training. The level of their pupils’ knowledge about the disease had increased significantly (p < 0.05). However, pupils responded that, even after the educational activities, they still had contact with the city’s contaminated waters (p > 0.05).ConclusionsThe results of this study underline the importance of schools and teachers as partners in controlling and eliminating schistosomiasis. Teacher training on the disease significantly increases their pupils’ knowledge, reflecting empowerment with regard to local health conditions.

Unexpected Discovery of an Ectoparasitic Invasion First Detected in the Baikal Coregonid Fish Population

The omul, Coregonus migratorius (Georgi, 1775), an endemic fish of Lake Baikal, is the main commercial species of essential economic importance for the extensive region of Eastern Siberia. Despite the continuous 250-year study of Baikal omul and intensive commercial fishing, neither fishers nor biologists have ever mentioned or found external annelid parasites in numerous omul catches. Targeted parasitological studies have also never detected these ectoparasites on the body of this fish. In this study, we present the first reliable information on the existence of specific annelid parasites infecting the pelagic population of Baikal omul and report a 4% infestation of spawners in the Selenga River, the largest tributary of Lake Baikal. We also obtained the main morphometric parameters of the infected fishes, the morphology of the unknown parasite and its feeding strategy. DNA-based analysis was applied to ascertain the taxonomy of the leeches and revealed no closely related taxa existing in international genetic databases (e.g., GenBank) to date. A maximum genetic identity of 89–91% was detected with European Caspiobdella fadejewi. The genetic distances in 9–11% of the substitutions from the closest relatives were very high for a reliable molecular identification of a taxon. The Selenga omul leech may represent a potentially new species and genus.

Atypical Lesions in Canine Leishmaniosis: Description of New Cases.

Simple SummaryCanine leishmaniosis is a zoonotic disease caused mainly by the protozoan Leishmania infantum that is endemic in the Mediterranean basin. The clinical signs and pathological characteristics have been extensively described; however, atypical lesions leading to clinical and pathological misdiagnosis have been sporadically reported. This study presents three cases of dogs experimentally infected with Leishmania infantum that showed gross lesions considered atypical of canine leishmaniosis and not previously reported. Macroscopic lesions were observed in the liver, spleen, and peritoneal cavity that corresponded to tan to whitish nodular lesions in all organs and multifocal irregular and linear whitish lesions in one of the livers that mimicked tumors. Microscopically, a marked granulomatous inflammation with a relative scarcity of parasites was observed in all the organs. In conclusion, microscopic and parasitological studies should be performed on atypical lesions observed in Leishmania-infected and non-infected dogs, especially in endemic regions. In addition, due to its zoonotic importance, leishmaniosis should be considered when atypical nodular lesions are observed in dogs from non-endemic regions with a history of travel to endemic regions.Pathological characteristics are well described in canine leishmaniosis (CanL). However, atypical lesions that can be confused with other pathologies or trigger unusual clinical signs are sporadically reported. Atypical lesions were observed during routine postmortem examination in three Leishmania-infected dogs and samples were taken for histopathological and immunohistochemical studies. Clinical signs, biochemical parameters, level of antibodies, and parasite detection by PCR were also evaluated. Atypical lesions were found in the peritoneal cavity, liver, and spleen. Splenomegalia and hepatomegalia were observed in all dogs. In addition, multifocal dark to white nodules of variable size were observed in the peritoneal cavity, liver, and spleen of one dog and in the spleen of the other two dogs. One dog presented diffuse irregular whitish lines with a threadlike appearance and another an intense fibrotic depression in the intermediate lobe. Microscopically, an intense granulomatous inflammation with abundant macrophages, a variable number of lymphocytes, and a low to moderate number of parasites was observed. This study represents the first description of granulomatous peritonitis associated with Leishmania in dogs. It also shows atypical macroscopic expression of hepatitis in CanL. In the absence of an adequate clinical history and laboratory analyses, certain lesions observed in CanL could admit alternative diagnoses.

Parasitological and histopathological studies to the effect of aqueous extract of Moringa oleifera Lam. leaves combined with praziquantel therapy in modulating the liver and spleen damage induced by Schistosoma mansoni to male mice

This study assessed the effectiveness of an aqueous extract of Moringa Oleifera Lam. leaves (MOL) alone or in combination with praziquantel (PZQ) drug targeting–infected mice with Schistosoma mansoni-induced liver and spleen damage. Mice were divided into eight groups control mice group treated orally with saline. PZQ group: non-infected mice treated orally with 300 mg/kg bwt PZQ three consecutive days. MOL group: non-infected mice treated orally with 150 mg/kg bwt MOL extract for 15 days. PZQ/ MOL group: non-infected mice treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. IF group: infected mice with 100 cercariae/mouse of the Egyptian strain of S. mansoni. IF/PZQ group infected mice with S. mansoni cercariae and treated orally with 300 mg/kg bwt PZQ for three consecutive days. IF/MOL group: infected mice with S. mansoni cercariae treated orally with 150 mg/kg bwt MOL extract for 15 days. IF/PZQ +MOL group: infected mice with S. mansoni cercariae treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. Blood, liver, spleen, worm, and eggs were collected at the end of the experimental period. Treatment of infected mice with MOL and PZQ together significantly reduced the number of ova/g tissue and eliminated the parasites. In addition, the liver and spleen of infected mice showed less histopathological alteration and immunohistochemical expression of nuclear factor kappa β (NF-Kβ). We can conclude that MOL extract combined with PZ has a curative effect on S. mansoni infection and helped to lessen its pathological effects.

Spatial and temporal parasite dynamics: microhabitat preferences and infection progression of two co-infecting gyrodactylids

BackgroundMathematical modelling of host-parasite systems has seen tremendous developments and broad applications in theoretical and applied ecology. The current study focuses on the infection dynamics of a gyrodactylid-fish system. Previous experimental studies have explored the infrapopulation dynamics of co-infecting ectoparasites, Gyrodactylus turnbulli and G. bullatarudis, on their fish host, Poecilia reticulata, but questions remain about parasite microhabitat preferences, host survival and parasite virulence over time. Here, we use more advanced statistics and a sophisticated mathematical model to investigate these questions based on empirical data to add to our understanding of this gyrodactylid-fish system.MethodsA rank-based multivariate Kruskal-Wallis test coupled with its post-hoc tests and graphical summaries were used to investigate the spatial and temporal parasite distribution of different gyrodactylid strains across different host populations. By adapting a multi-state Markov model that extends the standard survival models, we improved previous estimates of survival probabilities. Finally, we quantified parasite virulence of three different strains as a function of host mortality and recovery across different fish stocks and sexes.ResultsWe confirmed that the captive-bred G. turnbulli and wild G. bullatarudis strains preferred the caudal and rostral regions respectively across different fish stocks; however, the wild G. turnbulli strain changed microhabitat preference over time, indicating microhabitat preference of gyrodactylids is host and time dependent. The average time of host infection before recovery or death was between 6 and 14 days. For this gyrodactylid-fish system, a longer period of host infection led to a higher chance of host recovery. Parasite-related mortalities are host, sex and time dependent, whereas fish size is confirmed to be the key determinant of host recovery.ConclusionFrom existing empirical data, we provided new insights into the gyrodactylid-fish system. This study could inform the modelling of other host-parasite interactions where the entire infection history of the host is of interest by adapting multi-state Markov models. Such models are under-utilised in parasitological studies and could be expanded to estimate relevant epidemiological traits concerning parasite virulence and host survival.Graphical

Nitazoxanide, Ivermectin, and Artemether effects against cryptosporidiosis in diabetic mice: parasitological, histopathological, and chemical studies.

Human cryptosporidiosis is one of the most significant causes of water borne epidemics of diarrhea worldwide. It is extremely important in immunocompromised hosts and malnourished children as it could cause severe life-threatening diarrhea. Despite the global burden of the disease, there are only few available therapies against cryptosporidiosis. Diabetes mellitus is a common metabolic disorder that impair both the innate and adaptive immune responses of the patient. This study aimed to test the effect of Nitazoxanide, Ivermectin, and Artemether against cryptosporidiosis in diabetic mice. Sixty white albino mice were categorized into 6 groups; 10 mice each: GI: normal non-infected non-treated (healthy- control), GII-GVI (diabetic groups), GII: non-infected non treated (diabetic control), GIII: infected non treated (infected control), GIV: infected and treated with Nitazoxanide (NTZ), GV: infected and treated with Ivermectin (IVC), GVI: infected and treated with Artemether (ART). Parasitological, histopathological, and chemical examinations were done to evaluate the effect of NTZ, IVC, and ART against cryptosporidiosis in diabetic mice. Parasitological examination revealed maximum reduction of oocyst shedding in GVI, while histopathological examination showed the least pathologic changes in GV with mild vascular wall fibrosis and moderate lymphocytic infiltration of islets of Langerhans. Measurement of blood glucose level showed the best results with GIV. Nitazoxanide is effective against cryptosporidiosis in diabetic patients with minimal hyperglycemia, Artemether is especially effective in reducing the oocyst shedding in stool, whereas Ivermectin is associated with the least pathological changes in pancreatic islets of Langerhans.Graphical abstract