Therapeutic effects of benznidazole in Swiss mice that are orally inoculated with Trypanosoma cruzi IV strains from the Western Brazilian Amazon.

Strains of Trypanosoma cruzi, etiological agent of Chagas disease, are classified into different discrete typing units that may present distinct dynamics of infection and susceptibility to benznidazole (BZ) treatment. Mice that were orally inoculated with T. cruzi IV strains exhibited a more intense course of infection compared with intraperitoneally inoculated mice, reflected by higher parasite loads. We evaluated the efficacy of BZ treatment in Swiss mice that were inoculated with T. cruzi IV strains from the Western Brazilian Amazon. The mice were orally (OR) or intraperitoneally (IP) inoculated with 2 × 106 culture-derived metacyclic trypomastigotes of the AM14, AM16, AM64, and AM69 strains of T. cruzi that were obtained from two outbreaks of orally acquired acute Chagas disease in the state of Amazonas, Brazil. The animals were treated with BZ (100 mg/kg/day for 20 days). Fresh blood examination, hemoculture, conventional and quantitative real-time polymerase chain reaction were performed to monitor the therapeutic effects of BZ. Significant reductions in five of 24 parameters of parasitemia and parasite load were found in different tissues in the OR group, indicating worse response to BZ treatment compared with the IP group, in which significant reductions in nine of those 24 parameters were observed. The cure rates in the OR groups ranged from 18.2% (1/11) to 75.0% (9/12) and in the IP groups from 58.3% (7/12) to 91.7% (11/12), for the AM14 and AM69 strains, respectively. These findings indicate that treatment with BZ had fewer beneficial effects with regard to reducing parasitemia and parasite load in different tissues of mice that were OR inoculated with four TcIV strains compared with IP inoculation. Therefore, the route of infection with T. cruzi should be considered when evaluating the therapeutic efficacy of BZ in patients with Chagas disease.

Case Report: Atypical Presentation of Visceral Leishmaniasis: Two Cases from Northwest Ethiopia.

Human visceral leishmaniasis (VL) is a life-threatening disease caused by protozoan parasites belonging to the Leishmania donovani complex. Atypical cases of leishmaniasis and HIV coinfection have been documented in case reports, mostly associated with gastrointestinal tract, kidney, and skin involvement. We report two VL cases with atypical localizations not reported from east Africa before, both diagnosed and treated at the Leishmaniasis Research and Treatment Center, Gondar, Ethiopia. The first case was an HIV-infected patient with scrotal and penile involvement. Leishmania parasites were detected in the spleen and the scrotum. The second case was an immunocompetent individual with esophageal, laryngeal, and pharyngeal involvement and facial lesions. Leishmania parasites were detected in the spleen, skin, and esophageal biopsies. Current evidence suggests atypical presentation can occur in patients irrespective of their HIV status. Therefore, we suggest a high index of suspicion for VL among clinicians working in endemic areas of Ethiopia.

Diagnosis of oesophageal mucormycosis managed with medical therapy alone.

Mucormycosis is an invasive mould that can cause aggressive infection, particularly in immunocompromised patients. Though oesophageal mucormycosis is relatively rare, it remains an elusive and devastating manifestation of this disease. The management is also challenging, due to surgical morbidity and contraindications such as thrombocytopenia in immunocompromised hosts. In this report, we present the case of a 60-year-old Lebanese man with newly diagnosed acute myeloid leukaemia who developed oesophageal mucormycosis after induction chemotherapy with idarubicin/cytarabine (7+3). The diagnosis was made when the patient developed febrile neutropenia and odynophagia. CT scan of the chest revealed a thickened oesophagus. Oesophagogastroduodenoscopy with biopsy, histopathology and PCR were performed, resulting in the diagnosis of Rhizopus microsporus The patient was successfully treated with liposomal amphotericin B and salvage posaconazole therapy without surgical intervention. We reviewed the clinical characteristics of the six published oesophageal mucormycosis reports from the literature.

The esophageal gland mediates host immune evasion by the human parasite Schistosoma mansoni.

Schistosomes are parasitic flatworms that cause schistosomiasis, a neglected tropical disease affecting over 200 million people. Schistosomes develop multiple body plans while navigating their complex life cycle, which involves two different hosts: a mammalian definitive host and a molluscan intermediate host. Their survival and propagation depend upon proliferation and differentiation of stem cells necessary for parasite homeostasis and reproduction. Infective larvae released from snails carry a handful of stem cells that serve as the likely source of new tissues as the parasite adapts to life inside the mammalian host; however, the role of these stem cells during this critical life cycle stage remains unclear. Here, we characterize stem cell fates during early intramammalian development. Surprisingly, we find that the esophageal gland, an accessory organ of the digestive tract, develops before the rest of the digestive system is formed and blood feeding is initiated, suggesting a role in processes beyond nutrient uptake. To explore such a role, we examine schistosomes that lack the esophageal gland due to knockdown of a forkhead-box transcription factor, Sm-foxA, which blocks development and maintenance of the esophageal gland, without affecting the development of other somatic tissues. Intriguingly, schistosomes lacking the esophageal gland die after transplantation into naive mice, but survive in immunodeficient mice lacking B cells. We show that parasites lacking the esophageal gland are unable to lyse ingested immune cells within the esophagus before passing them into the gut. These results unveil an immune-evasion mechanism mediated by the esophageal gland, which is essential for schistosome survival and pathogenesis.

Immunoreactive Proteins in the Esophageal Gland Cells of Anisakis Simplex Sensu Stricto Detected by MALDI-TOF/TOF Analysis.

In plant and animal nematode parasites, proteins derived from esophageal gland cells have been shown to be important in the host-nematodes relationship but little is known about the allergenic potential of these proteins in the genus Anisakis. Taking into account the increase of anisakiasis and allergies related to these nematodes, immunoreactive properties of gland cell proteins were investigated. Two hundred ventricles were manually dissected from L3 stage larvae of Aniskakis simplex s.s. to allow direct protein analysis. Denaturing gel electrophoresis followed by monochromatic silver staining which revealed the presence of differential (enriched) proteins when compared to total nematode extracts. Such comparison was performed by means of 1D and 2D electrophoresis. Pooled antisera from Anisakis spp.-allergic patients were used in western blots revealing the presence of 13 immunoreactive bands in the ventricular extracts in 1D, with 82 spots revealed in 2D. The corresponding protein bands and spots were excised from the silver-stained gel and protein assignation was made by MALDI-TOF/TOF. A total of 13 (including proteoforms) were unambiguously identified. The majority of these proteins are known to be secreted by nematodes into the external environment, of which three are described as being major allergens in other organisms with different phylogenetic origin and one is an Anisakis simplex allergen.

First report of Anisakis sp. (Nematoda: Anisakidae) parasitizing Muscovy duck in Marajó Island, state of Pará, Brazil.

Among the avian used for human consumption, the Muscovy duck is well adapted to various climatic conditions and its breeding is widespread due to its easy handling, and its meat is widely consumed and appreciated, especially in the cuisine of northern Brazil. The present study aimed to report and identify taxonomically the nematodes found in the esophagus of Muscovy ducks reared and marketed in the municipality of Soure, Marajó Island, state of Pará, Brazil, and discuss its zoonotic potential to human. The samples consisted of 30 specimens of Cairina moschata domestica analyzed. A total of 258 nematodes were recovered, which were strongly fixed in the esophageal mucosa of hosts. The morphological and morphometric characteristics were compatible with Anisakis third-stage larvae.

[Human Gongylonema pulchrum infection in esophagus: a case report].

This paper reports a female patient with Gongylonema pulchrum parasitizing in the esophagus, with aims to call for the attention to the role of parasite detection in the diagnosis of human diseases.

Molecular identification of sarcocysts from tissue of fallow deer (Dama dama) farmed in the open pasture system based on ssu rRNA gene.

PURPOSE: Sarcocystis spp. are protozoan parasites of livestock which also infect birds, lower vertebrates and mammals, including man. Wild and domestic ruminants such as red deer, roe deer, fallow deer, cattle, sheep and goats may act as intermediate hosts for many Sarcocystis species, some of which are significant pathogens causing sarcocystosis in livestock and humans. The purpose of the present study was to determine the prevalence of Sarcocystis species in fallow deer farmed in an open pasture system. METHODS: Samples of heart and oesophagus tissue taken from five fallow deer were examined by light microscope for the presence of sarcocysts. Genomic DNA was extracted from individual sarcocysts. ssu rRNA was successfully amplified using their DNA as templates. RESULTS: Analysis of the ssu rRNA identified the presence of two S. morae sarcocysts in the heart tissue; similarly, S. gracilis sarcocysts were identified in the heart and oesophagus, and Sarcocystis sp. most closely related to S. linearis and S. taeniata were detected in oseophagus. CONCLUSIONS: These findings confirm the presence of Sarcocystis spp. in farmed fallow deer in Poland; however, more molecular studies are needed.

Ithyoclinostomum yamagutii n. sp. (Digenea: Clinostomidae) in the great blue heron Ardea herodias L. (Aves: Ardeidae) from Mississippi, USA.

With only six recognised genera, the family Clinostomidae Lühe, 1901 remains a global research interest of parasitologists and ecologists. Recent efforts have focused on providing molecular data to investigate species diversity, elucidate life-cycles, and make inferences on the group's evolutionary history. Of the clinostomid genera, the monotypic Ithyoclinostomum Witenberg, 1926 has remained more enigmatic compared to the commonly encountered Clinostomum Leidy, 1856. Recent morphological and molecular evidence from metacercariae suggests a second Ithyoclinostomum species may exist in freshwater cichlids in Central America and Mexico. In a recent survey of great blue herons Ardea herodias L. from commercial catfish production farms in Mississippi, USA, two specimens of an abnormally large (> 20 mm) clinostomid were encountered in the oesophagus of a single bird. These specimens were identified as an Ithyoclinostomum sp. morphologically distinct from the only nominal species Ithyoclinostomum dimorphum (Diesing, 1850). Using morphological and molecular data these adult specimens were confirmed as conspecific with the larval metacercariae previously described from Central America and Mexico and represent the novel species, Ithyoclinostomum yamagutii n. sp.

First report of Anisakis sp. (Nematoda: Anisakidae) parasitizing Muscovy duck in Marajó Island, state of Pará, Brazil / Primeiro relato de Anisakis sp. (Nematoda: Anisakidae) parasitando pato doméstico na Ilha de Marajó, estado do Pará, Brasil

Abstract Among the avian used for human consumption, the Muscovy duck is well adapted to various climatic conditions and its breeding is widespread due to its easy handling, and its meat is widely consumed and appreciated, especially in the cuisine of northern Brazil. The present study aimed to report and identify taxonomically the nematodes found in the esophagus of Muscovy ducks reared and marketed in the municipality of Soure, Marajó Island, state of Pará, Brazil, and discuss its zoonotic potential to human. The samples consisted of 30 specimens of Cairina moschata domestica analyzed. A total of 258 nematodes were recovered, which were strongly fixed in the esophageal mucosa of hosts. The morphological and morphometric characteristics were compatible with Anisakis third-stage larvae.

Resumo Entre as aves utilizadas para consumo humano, o pato doméstico está bem adaptado às várias condições climáticas. Sua criação é muito difundida devido ao seu fácil manejo. E sua carne é amplamente consumida e apreciada, principalmente na culinária do norte do Brasil. O presente estudo teve como objetivo relatar e identificar taxonomicamente os nematódeos encontrados no esôfago de patos domésticos, criados e comercializados no município de Soure, Ilha de Marajó, estado do Pará, Brasil. E também discutir o seu potencial zoonótico para o homem. As amostras consistiram em 30 espécimes de Cairina moschata domestica analisados. Um total de 258 nematódeos foram recuperados, fortemente fixados na mucosa esofágica dos hospedeiros. As características morfológicas e morfométricas foram compatíveis com as larvas de terceiro estágio de Anisakis.

Histopathological Survey on Sarcocystis Species Infection in Slaughtered Cattle of Zabol-Iran

Objective: Sarcocystosis is an important zoonotic protozoal disease with worldwide distribution and wide range of hosts. The aim of the present study was to determine the intensity of Sarcocystis spp. infection and to show histopathological features of their cystic lesions in slaughtered cattle of Zabol- Iran. Methods: From April to September 2018, 500 tissue samples from esophagus, heart, diaphragm, tongue and masticatory muscles were prepared from 100 slaughtered cattle. All samples were fixed in 10% neutral buffered formalin and routine tissue processing protocol was performed. Results: The microscopic results showed that 92.2% of specimens had thin-walled cysts of S. cruzi and 14% had thick-walled Sarcocystis (S. hirsuta and S. hominis) but macrocyst was only observed in one cattle. The positivity rate of thin walled cysts was 58.8% for heart, 13.9% for masticatory muscles, 10.2% for tongue, 9.3% for esophagus and 7.8% for diaphragm. The positivity rate of thick walled cysts was 32.8% for esophagus, 28.6% for tongue, 22.9% for heart, 15.7% for masticatory muscles and 0% for diaphragm, which could represent either S. hominis or S. hirsuta. The most infected tissue was heart and the least infected tissue was diaphragm. Thin walled cysts (S. cruzi) were mostly found in heart and were less found in diaphragm. However, thick-walled cysts (S. hirsuta and S. hominis) were mostly detected in esophagus. No thick-walled cysts were found in diaphragm muscle. Conclusion: A high positivity rate of sarcocystosis in slaughtered cattle in Zabol abattoir revealed heavily environmental contamination of Sistan region by this important parasitic disease.

Morphological, Molecular, and Histopathological Data for Sebekia mississippiensis Overstreet, Self, and Vliet, 1985 (Pentastomida: Sebekidae) in the American Alligator, Alligator mississippiensis Daudin, and the Spotted Gar, Lepisosteus oculatus Winchell.

Novel molecular data from both mitochondrial ( cytochrome c oxidase subunit 1) and ribosomal regions ( 18S, ITS1-5.8S, ITS2, and 28S) are provided for Sebekia mississippiensis Overstreet, Self, & Vliet, 1985 , a pentastome infecting the American alligator, Alligator mississippiensis Daudin, 1801, and the spotted gar, Lepisosteus oculatus Winchell, 1864. Adult and nymphal pentastomes are described from the lungs and liver of the type host, A. mississippiensis, collected from Mississippi, while additional nymphs are described from the esophageal lining of L. oculatus specimens collected from Louisiana. This sequencing data will facilitate more accurate identification of various life cycle stages of S. mississippiensis, enabling future work to resolve many ambiguities in the literature regarding this species. Additionally, histopathological data are provided from both the definitive and intermediate hosts.

Occurrence of Sarcocystis gigantea macrocysts and high frequency of S. tenella microcysts in sheep from southern Brazil.

The aim of this study was to investigate the occurrence of sarcocysts in sheep slaughtered in the Rio Grande do Sul state, Brazil. Heart and esophagus samples from 130 sheep were subjected to macroscopic and microscopic examination, followed by molecular analysis. Ten sheep (7.7%) had Sarcocystis gigantea macrocysts in esophagus, as identified by gene sequencing. Microcysts were present in 96.1% of the sheep, with a higher frequency (p < .05) in the heart (91.5%) compared to the esophagus (81.5%) samples. The microcysts were identified as Sarcocystis tenella by gene sequencing. Our results revealed a high frequency of Sarcocystis spp. infection in sheep from southern Brazil. To the authors knowledge, this is the first molecular confirmation of S. gigantea presence in Brazil.

Kudoa amazonica n. sp. (Myxozoa; Multivalvulida), a parasite of the esophageal musculature of the freshwater catfish, Hypophthalmus marginatus (Siluriformes: Pimelodidae), from a river of the Amazon region.

The class Myxozoa is a group of spore-producing eukaryote organisms that parasitize both freshwater and marine fish. The multivalvulide myxosporidian parasites of the genus Kudoa infect primarily the musculature of the fish host, some species are producing enzymes (proteases) capable of digesting muscle fibers. In the present study, 50 specimens of the freshwater catfish Hypophthalmus marginatus were collected from the Tocantins River in Pará, Brazil, and were analyzed. Overall, 68% of these specimens presented infections by Kudoa parasite in the esophageal musculature. The morphology of these parasite was examined under light microscopy and nucleotide sequences of the SSU rDNA gene were obtained for phylogenetic analyses. The species formed numerous whitish pseudocysts containing square spores with rounded extremities in the apical view, and four polar capsules of equal size. In the phylogenetic analyses, Kudoa amazonica n. sp. was characterized as a sister taxon of another freshwater species, Kudoa orbicularis. The combination of morphological, morphometric, and molecular data obtained in the present study provided a conclusive diagnosis of Kudoa amazonica n. sp., which is clearly distinct from all other Kudoa taxa described to date.

Spirocerca vulpis sp. nov. (Spiruridae: Spirocercidae): description of a new nematode species of the red fox, Vulpes vulpes (Carnivora: Canidae).

Previous studies have reported nematodes of the Spirocercidae family in the stomach nodules of red foxes (Vulpes vulpes) described as Spirocerca sp. or Spirocerca lupi (Rudolphi, 1819). We characterized spirurid worms collected from red foxes and compared them to S. lupi from domestic dogs by morphometric and phylogenetic analyses. Nematodes from red foxes differed from S. lupi by the presence of six triangular teeth-like buccal capsule structures, which are absent in the latter. Additionally, in female worms from red foxes, the distance of the vulva opening to the anterior end and the ratio of the glandular-to-muscular oesophagus lengths were larger than those of S. lupi (P < 0.006). In males, the lengths of the whole oesophagus and glandular part, the ratio of the glandular-to-muscular oesophagus and the comparison of the oesophagus to the total body length were smaller in S. lupi (all P < 0.044). Phylogenetic analyses revealed that S. lupi and the red foxes spirurid represent monophyletic sister groups with pairwise nucleotide distances of 9.2 and 0.2% in the cytochrome oxidase 1 and 18S genes, respectively. Based on these comparisons, the nematodes from red foxes were considered to belong to a separate species, for which the name Spirocerca vulpis sp. nov. is proposed.

Three new species of Clinostomum Leidy, 1856 (Trematoda) from Middle American fish-eating birds.

We recently engaged in a two-part study of Clinostomum Leidy, 1856 across a geographic range comprising central Mexico southwards to Costa Rica, in Central America. In the first study, we investigated the species boundaries by using DNA sequences of mitochondrial and nuclear molecular markers, implementing several analytical tools and species delimitation methods. The result of that approach revealed five highly divergent genetic lineages that were interpreted as independent evolutionary units, or species. Here, we present the second part of the study, where we describe three of the five species for which we have sexually mature adult specimens obtained from the mouth cavity of fish-eating birds. Additionally, we characterise morphologically the metacercariae of the other two species, collected from freshwater fishes; these species cannot be formally described since no adults were found in their definitive hosts. We further discuss the characters that are more reliable for species identification within Clinostomum, such as the cirrus sac shape and relative position with respect to testes and ovary, the shape of the reproductive organs, and the diverticulated condition of the caeca.

Evaluation of a spot-on imidacloprid-moxidectin formulation (Advocate®) for the treatment of naturally occurring esophageal spirocercosis in dogs: a double-blinded, placebo-controlled study.

BACKGROUND: Dogs are the definitive hosts of Spirocerca lupi. Spirocercosis is treated by prolonged avermectin administration by injection or daily oral doses. In this prospective, double-blinded, placebo-controlled, clinical trial, the efficacy of imidacloprid and moxidectin spot-on formulation (Advocate®) was compared to injectable doramectin (Dectomax®). Dogs diagnosed with benign esophageal spirocercosis were divided randomly into doramectin (400 µg/kg IM) or moxidectin and imidacloprid spot-on (2.5-6.25 mg/kg and 10-25 mg/kg, respectively) groups and treated weekly for 12 consecutive weeks. Dogs were followed for 20 weeks by physical examination, owners' questionnaire, blood work, fecal floatation, PCR and endoscopy. RESULTS: All the doramectin group dogs (n = 10) completed the treatment and follow-up, and the disease had completely resolved in all by week 12. Of the Advocate® group (n = 10), four had complete resolution at week 12, four had partial resolution, one dog did not respond to treatment, and one dog was switched to the doramectin protocol on week 5 due to persistent severe clinical signs. PCR analysis was more sensitive in detecting S. lupi eggs compared to fecal floatation. Discrepancies were detected on 22 occasions, of which on 20 occasions, the PCR was positive while fecal floatation was negative, and only on two occasions the PCR results were negative while fecal flotation was positive. CONCLUSIONS: The present results indicate that weekly Advocate® spot-on administration may be effective for treating benign esophageal spirocercosis, but is less effective than the currently used injectable doramectin therapy at the dose and duration used herein.