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Metacestode infestation of Semibalanus balanoides (L., 1767) and Balanus crenatus Bruguiеre, 1789, collected in the Barents and White Seas and in the northern part of the Sea of Okhotsk in 2020 and 2021, respectively, was studied. A total of 313 S. balanoides from Mogilnaya Bay of Kildin Island (Barents Sea) and isolated mature wrinkled barnacles B. crenatus, two and four specimens from the Pechora Sea and Kandalaksha Bay of the White Sea, respectively, were examined in 2020. Metacestodes Fimbriarioides intermedia (Fuhrmann, 1913) (Cyclophyllidea, Hymenolepididae) were found in 1.0 ± 0.6% of S. balanoides in the Barents Sea with an invasion intensity (I. I.) of 2–5 specimens, and in one of two B. crenatus from the Pechora Sea (I. I. 15 specimens). For the first time, in both B. crenatus from the Pechora Sea, taken from the valves of the mussel Mytilus edulis, metacestodes Microsomacanthus sp. I (I. I. 13 and 20 specimens) with proboscis hooks 38–41 (39.4 ± 0.1) µm long and blades of 9.5–11 (10.7 ± 0.1) µm were obtained. One of four B. crenatus from the Kandalaksha Bay was infected with another Microsomacanthus sp. II (I. I. 19 specimens) with proboscis hooks 44.0–49.5 (45.7 ± 0.5) µm long and blades 14.0–16.0 (14.8 ± 0.07) µm long. A total of 362 S. balanoides were collected and dissected in Gizhiginskaya Bay of the northern part of the Sea of Okhotsk in 2021, of which 8.0 ± 1.4% were infected with F. intermedia metacestodes (I. I. 1–19 specimens). Study results of the infestation of S. balanoides on the Koni-Pyagin coast of the Sea of Okhotsk (according to the collections of 2006–2007) were supplemented and clarified. Description of metacestodes and the taxonomic affiliation of cysticercoids Microsomacanthus spp. are given. [ABSTRACT FROM AUTHOR]

In medicine, parasitic cysts (e.g., brain cysticerci) are believed to be sterile, and are primarily treated with antiparasitic medications, not antibiotics, which could prevent abscess formation and localized inflammation. This study quantified the microbial composition of parasitic cysts in a wild rodent, using multi-kingdom metagenomics to comprehensively assess if parasitic cysts are sterile, and further understand gut microbial translocation and adaptation in wildlife confined environments, outside the gut. Analysis was conducted on DNA from two hepatic parasitic cysts from a feline tapeworm, Hydatigera (Taenia) taeniaeformis, affecting a wild vole mouse (Microtus pennsylvanicus), and from feces, liver and peritoneal fluid of this and two other concurrent individual wild voles trapped during pest control in one of our university research vegetable gardens. Bacterial metagenomics revealed the presence of gut commensal/opportunistic species, Parabacteroides distasonis, Bacteroides (Bacteroidota); Klebsiella variicola, E. coli (Enterobacteriaceae); Enterococcus faecium and Lactobacillus acidophilus (Bacillota) inhabiting the cysts, and peritoneal fluid. Remarkably, viral metagenomics revealed various murine viral species, and unexpectedly, a virus from the insect armyworm moth (Pseudaletia/Mythimna unipuncta), known as Mythimna unipuncta granulovirus A (MyunGV-A), in both cysts, and in one fecal and one peritoneal sample from the other non-cyst voles, indicating the survival and adaption potential of the insect virus in voles. Metagenomics also revealed a significantly lower probability of fungal detection in cysts compared to that in peritoneal fluid/feces (p < 0.05), with single taxon detection in each cyst (Malassezia and Pseudophaeomoniella oleicola). The peritoneal fluid had the highest probability for fungi. In conclusion, metagenomics revealed that bacteria/viruses/fungi coexist within parasitic cysts supporting the potential therapeutic benefits of antibiotics in cystic diseases, and in inflammatory microniches of chronic diseases, such as Crohn's disease gut wall cavitating micropathologies, from which we recently isolated similar synergistic pathogenic Bacteroidota and Enterobacteriaceae, and Bacillota. [ABSTRACT FROM AUTHOR]

Taenia crassiceps is a zoonotic tapeworm of the genus Taenia that is distributed throughout the Northern Hemisphere. Wild and domestic carnivores are final hosts, while rodents and rabbits are primarily intermediate hosts, although many other mammals may harbour the larval stage, Cysticercus longicollis. This case report aims to describe C. longicollis infection in a lemur and molecularly characterise the isolated parasite. The excised lesion was subjected to morphological and histopathological examination, which revealed cysticerci of the tapeworm. Formalin-fixed and paraffin-embedded block (FFPEB), as well as the cysticerci fixed with formalin stored for one year, were subjected to molecular analysis, which aimed at detecting the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of Taenia sp. Based on the morphological characteristics, the parasite was identified as a metacestode of T. crassiceps. The presence of the cox1 gene was detected using polymerase chain reaction (PCR) in all samples. A randomly selected PCR product was sequenced and compared with other sequences from the GenBank database, confirming that the detected parasite was T. crassiceps. This article reports the first case of T. crassiceps cysticercosis in a lemur (Lemur catta) in Croatia and emphasises the potential risk of transmission from wild carnivores. [ABSTRACT FROM AUTHOR]

Two adult male Puerto Rican crested anoles (Anolis cristatellus cristatellus) housed in a research facility were presented with debilitation and were euthanized. On autopsy, anole 1 had a large cystic white structure in the left pelvic limb, which protruded through the ruptured epidermis, and a large, poorly demarcated swelling in the right caudal abdomen. Anole 2 had masses in the mid-dorsum, caudal dorsum, left pelvic limb, and tail. These masses contained variably sized cestode larvae, which ruptured into the coelomic cavity. Evaluation of the larvae revealed a thickened and wrinkled anterior end, with a cleft-like invagination, consistent with either a plerocercoid sparganum or a tetrathyridium. Histologically, several cestode larvae were contained in the body wall of both anoles. These were up to 650 μm in diameter, with a thin tegument and a spongy parenchyma. The spongy parenchyma contained numerous, up to 30 μm diameter, sharply demarcated, basophilic-to-black structures (calcareous corpuscles). There was pneumonia and hepatitis in anole 2, suggestive of potential secondary infection subsequent to immunosuppression. Molecular amplification of the cytochrome C oxidase subunit 1 revealed 100% homology for the COX1 gene of the diphyllobothriid tapeworm Spirometra erinaceieuropaei, also known as Spirometra mansoni. [ABSTRACT FROM AUTHOR]

Background: Tapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed de novo from a population of stem cells called germinative cells. This process is difficult to study for human pathogens, as these larvae are infectious and difficult to obtain in the laboratory. Methods: In this work, we analyzed cell proliferation and differentiation during larval metamorphosis in the model tapeworm Hymenolepis microstoma, by in vivo labelling of proliferating cells with the thymidine analogue 5-ethynyl-2'-deoxyuridine (EdU), tracing their differentiation with a suite of specific molecular markers for different cell types. Results: Proliferating cells are very abundant and fast-cycling during early metamorphosis: the total number of cells duplicates every ten hours, and the length of G2 is only 75 minutes. New tegumental, muscle and nerve cells differentiate from this pool of proliferating germinative cells, and these processes are very fast, as differentiation markers for neurons and muscle cells appear within 24 hours after exiting the cell cycle, and fusion of new cells to the tegumental syncytium can be detected after only 4 hours. Tegumental and muscle cells appear from early stages of metamorphosis (24 to 48 hours postinfection); in contrast, most markers for differentiating neurons appear later, and the detection of synapsin and neuropeptides correlates with scolex retraction. Finally, we identified populations of proliferating cells that express conserved genes associated with neuronal progenitors and precursors, suggesting the existence of tissue-specific lineages among germinative cells. Discussion: These results provide for the first time a comprehensive view of the development of new tissues during tapeworm larval metamorphosis, providing a framework for similar studies in human and veterinary pathogens. [ABSTRACT FROM AUTHOR]

Hydatigera taeniaeformis is a cestode that uses felines and rodents as definitive and intermediate hosts, respectively. Its larval stage, or metacestode, infects a wide variety of rodent species and develops in the liver parenchyma into a cyst. The aim of this study was to evaluate the occurrence of H. taeniaeformis metacestode in various species of wild rodents from Peru. For this, the livers of 356 rodents were macroscopically examined for any parasitic form compatible with metacestodes. Metacestodes were identified by measuring characteristic morphological parameters, and the diagnosis was confirmed by molecular analysis of a fragment of the cytochrome c oxidase subunit 1 gene (cox1). Five rodents: two small-eared pygmy rice rats (Oligoryzomys microtis), two white-naped squirrels (Simosciurus nebouxii), and one pygmy rice rat (Oligoryzomys sp.) were infected with H. taeniaeformis metacestodes. The cox1 sequences from our metacestodes showed up to 100% identity with previous H. taeniaeformis sequences from the GenBank. These results demonstrated the occurrence of H. taeniaeformis in new intermediate hosts, as well as the first molecular contribution for H. taeniaeformis from Peru. [ABSTRACT FROM AUTHOR]

Taenia crassiceps is a zoonotic tapeworm of the genus Taenia that is distributed throughout the Northern Hemisphere. Wild and domestic carnivores are final hosts, while rodents and rabbits are primarily intermediate hosts, although many other mammals may harbour the larval stage, Cysticercus longicollis. This case report aims to describe C. longicollis infection in a lemur and molecularly characterise the isolated parasite. The excised lesion was subjected to morphological and histopathological examination, which revealed cysticerci of the tapeworm. Formalin-fixed and paraffin-embedded block (FFPEB), as well as the cysticerci fixed with formalin stored for one year, were subjected to molecular analysis, which aimed at detecting the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of Taenia sp. Based on the morphological characteristics, the parasite was identified as a metacestode of T. crassiceps. The presence of the cox1 gene was detected using polymerase chain reaction (PCR) in all samples. A randomly selected PCR product was sequenced and compared with other sequences from the GenBank database, confirming that the detected parasite was T. crassiceps. This article reports the first case of T. crassiceps cysticercosis in a lemur (Lemur catta) in Croatia and emphasises the potential risk of transmission from wild carnivores.

BackgroundTapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed de novo from a population of stem cells called germinative cells. This process is difficult to study for human pathogens, as these larvae are infectious and difficult to obtain in the laboratory.MethodsIn this work, we analyzed cell proliferation and differentiation during larval metamorphosis in the model tapeworm Hymenolepis microstoma, by in vivo labelling of proliferating cells with the thymidine analogue 5-ethynyl-2′-deoxyuridine (EdU), tracing their differentiation with a suite of specific molecular markers for different cell types. ResultsProliferating cells are very abundant and fast-cycling during early metamorphosis: the total number of cells duplicates every ten hours, and the length of G2 is only 75 minutes. New tegumental, muscle and nerve cells differentiate from this pool of proliferating germinative cells, and these processes are very fast, as differentiation markers for neurons and muscle cells appear within 24 hours after exiting the cell cycle, and fusion of new cells to the tegumental syncytium can be detected after only 4 hours. Tegumental and muscle cells appear from early stages of metamorphosis (24 to 48 hours post-infection); in contrast, most markers for differentiating neurons appear later, and the detection of synapsin and neuropeptides correlates with scolex retraction. Finally, we identified populations of proliferating cells that express conserved genes associated with neuronal progenitors and precursors, suggesting the existence of tissue-specific lineages among germinative cells. DiscussionThese results provide for the first time a comprehensive view of the development of new tissues during tapeworm larval metamorphosis, providing a framework for similar studies in human and veterinary pathogens.

We report here Taenia lynciscapreoli metacestode from the lung lobe of a semi-domesticated reindeer (Rangifer tarandus tarandus). The specimen was detected within a development project concerning remote post mortem inspection at a reindeer abattoir in Sweden. Post mortem inspection was performed according to a routine on-site official meat inspection protocol. The species identification to T. lynciscapreoli was confirmed based on the DNA extracted from the metacestode, which was analysed by sequencing of the cytochrome c oxidase subunit 1. Firstly, our finding shows that semi-domesticated reindeer in addition to several other cervids can act as an additional intermediate host for T. lynciscapreoli. Secondly, it further confirms that this parasite is more widely distributed on the Scandinavian peninsula than what has previously been shown. This is in line with a previous molecular finding of adult T. lynciscapreoli from the Eurasian lynx (Lynx lynx) in Sweden and demonstrates that new intermediate host can be detected. Whether the present finding can be regarded as accidental or have created opportunities for an expansion throughout the northernmost Scandinavian Peninsula remains to be seen.

Taenia crassiceps is a parasite of wild canids and dogs that serve as definite hosts, harboring the adult cestode, whereas rodents are the intermediate hosts in which the metacestode/cysticercus/larval stage occurs. Fecal-oral transmission ensures the parasite's lifecycle. At times, dogs and humans act as accidental intermediate hosts. Despite the public health concern this parasite warrants, its epidemiology remains unclear. In this report, we document the occurrence of metacestodes of T. crassiceps in a muskrat (Ondatra zibethicus) and a domestic dog from the northeastern United States, a development that necessitates increased awareness and surveillance to tackle this disease of "one health" significance. Taenia crassiceps cysticercosis was confirmed in an adult male muskrat in February 2018 and in a 4-year-old female spayed Staffordshire Bull Terrier in December 2020. Parasitological and histopathologic examination of both cases revealed cysticerci with the characteristic rostellar hook morphology that aided in Taenia species identification. In the muskrat case specifically, partial sequencing of the mitochondrial cytochrome oxidase gene confirmed the species identity as T. crassiceps. We report T. crassiceps occurrence in a muskrat in New York State for the first time and document a case presentation in a domestic dog from New Jersey that was infected with metacestode stages of this parasite. Given the detection of this parasite in the northeastern United States, T. crassiceps infection, which otherwise is considered a rare disease, should be on the radar of veterinary, medical and wildlife biologists for timely diagnosis and interventions. [ABSTRACT FROM AUTHOR]

Purpose: Porcine cysticercosis is a neglected zoonotic disease of significant veterinary and medical importance owing to its economic impact and public health significance. The present study aimed at genetic characterization of Taenia solium metacestodes in slaughtered pigs of Haryana (North India). Methods: A total of 213 (160 and 53 from Chandigarh and Hisar, respectively) slaughtered pigs intended for human consumption were screened for the presence of T. solium metacestodes. The retrieved metacestodes were confirmed molecularly based on the partial amplification of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene. Evolutionary divergence, haplotype and nucleotide diversities and neutrality indices of the retrieved isolates were also assessed. Results: Out of the 213 pigs, 2 (0.94%) revealed the presence of metacestodes involving 1 pig each from Chandigarh (0.62%) and Hisar (1.9%). The sequences obtained after custom sequencing were submitted to GenBank under the accession numbers LC661682-83. The present study haplotype clustered with haplotypes of Asian origin and showed variation from other haplotypes by 1–23 mutational steps. However, the present study isolates also showed nucleotide polymorphisms (A198T, A199G, A201T, G204A, T206A, C210T, T212G, T213A, T216G/A, T217C, T221C, C524T, G994A) at different positions, which indicated the presence of sub-lineages. Low nucleotide diversity (π = 0.020) and negative value of Tajima's D (− 1.304) observed for the haplotypes under consideration was indicative of purifying selection and recent population expansion. Conclusions: Our study confirms the circulation of T. solium Asian genotype (with distinct sub-lineages) in study area and recommends strict control measures to contain the zoonotic disease. [ABSTRACT FROM AUTHOR]

Taenia hydatigena is a cosmopolitan tapeworm that uses canids or felines as definitive hosts, while the larval stage (metacestode), formerly referred to as cysticercus tenuicollis, infects a wide variety of intermediate hosts, in particular ruminants. In the present study, we used partial nucleotide sequences of the cox1 and nad1 genes of T. hydatigena from different animal species to analyse the intraspecies genetic diversity of this economically important parasite. Twenty-four samples of metacestodes or adults of T. hydatigena from infected sheep, chamois, roe deer, fallow deer, wild boar, and dogs from Slovakia were collected and further analysed. Several haplotypes of T. hydatigena were identified with unique mutations that have not been previously recorded in Slovakia. Analysis of nucleotide polymorphism revealed the existence of 9 and 13 haplotypes, with relatively low nucleotide pairwise divergence ranging between 0.3–1.3 and 0.2–1.8% for the Hcox and Hnad haplotypes, respectively. In general, low nucleotide and high haplotype diversities in the overall population of T. hydatigena from the study indicate a high number of closely related haplotypes within the explored population; nucleotide diversity per site was low for cox1 (Pi = 0.00540) and slightly higher for nad1 (Pi = 0.00898). A molecular study confirmed the existence of genetic variation within T. hydatigena isolates from Slovakia. However, further investigations with more samples collected from different intermediate and definitive hosts are required in order to investigate the epidemiological significance of the apparent genetic differences observed in this study. [ABSTRACT FROM AUTHOR]

The current chemotherapeutical treatment against alveolar echinococcosis relies exclusively on benzimidazoles, which are not parasiticidal and can induce severe toxicity. There are no alternative treatment options. To identify novel drugs with activity against Echinococcus multilocularis metacestodes, researchers have studied potentially interesting drug targets (e.g. the parasite's energy metabolism), and/or adopted drug repurposing approaches by undertaking whole organism screenings. We here focus on drug screening approaches, which utilize an in vitro screening cascade that includes assessment of the drug-induced physical damage of metacestodes, the impact on metacestode viability and the viability of isolated parasite stem cells, structure-activity relationship (SAR) analysis of compound derivatives, and the mode of action. Finally, once in vitro data are indicative for a therapeutic window, the efficacy of selected compounds is assessed in experimentally infected mice. Using this screening cascade, we found that the anti-malarial mefloquine was active against E. multilocularis metacestodes in vitro and in vivo. To shed more light into the mode of action of mefloquine, SAR analysis on mefloquine analogues was performed. E. multilocularis ferritin was identified as a mefloquine-binding protein, but its precise role as a drug target remains to be elucidated. In mice that were infected either intraperitoneally with metacestodes or orally with eggs, oral treatment with mefloquine led to a significant reduction of parasite growth compared to the standard treatment with albendazole. However, mefloquine was not acting parasiticidally. Assessment of mefloquine plasma concentrations in treated mice showed that levels were reached which are close to serum concentrations that are achieved in humans during long-term malaria prophylaxis. Mefloquine might be applied in human AE patients as a salvage treatment. Future studies should focus on other repurposed anti-infective compounds (MMV665807, niclosamide, atovaquone), which showed stronger in vitro activity against E. multilocularis than mefloquine.

Appropriate medical management can be an alternative in those patients with submacular cysticercosis in whom achieving good visual outcome with vitreoretinal surgery is not possible. We report the case of a 25-year-old female who presented complaining of blurred vision in her left eye associated with photopsias and metamorphopsias of 3 months duration. Initial visual acuity in the right eye was 20/20 and 20/100 in the left eye. Upon indirect ophthalmoscopy in the left eye, a yellow-white, dome-shaped, elevated lesion with foveal involvement was observed. The rest of the ophthalmological examination proved normal. With clinical findings and images, submacular cysticercosis was diagnosed, and vitreoretinal surgery was suggested. Nevertheless, the patient did not accept the treatment; therefore, medical management was initiated. Central nervous system involvement was ruled out, and treatment with praziquantel and systemic prednisolone was initiated. Cysticercosis was resolved with significant improvement of her symptoms and visual acuity.

Taenia crassiceps is a parasite of wild canids and dogs that serve as definite hosts, harboring the adult cestode, whereas rodents are the intermediate hosts in which the metacestode/cysticercus/larval stage occurs. Fecal-oral transmission ensures the parasite’s lifecycle. At times, dogs and humans act as accidental intermediate hosts. Despite the public health concern this parasite warrants, its epidemiology remains unclear. In this report, we document the occurrence of metacestodes of T. crassiceps in a muskrat (Ondatra zibethicus) and a domestic dog from the northeastern United States, a development that necessitates increased awareness and surveillance to tackle this disease of “one health” significance. Taenia crassiceps cysticercosis was confirmed in an adult male muskrat in February 2018 and in a 4-year-old female spayed Staffordshire Bull Terrier in December 2020. Parasitological and histopathologic examination of both cases revealed cysticerci with the characteristic rostellar hook morphology that aided in Taenia species identification. In the muskrat case specifically, partial sequencing of the mitochondrial cytochrome oxidase gene confirmed the species identity as T. crassiceps. We report T. crassiceps occurrence in a muskrat in New York State for the first time and document a case presentation in a domestic dog from New Jersey that was infected with metacestode stages of this parasite. Given the detection of this parasite in the northeastern United States, T. crassiceps infection, which otherwise is considered a rare disease, should be on the radar of veterinary, medical and wildlife biologists for timely diagnosis and interventions.

Abstract Background Taenia multiceps is a harmful tapeworm and its larval form (coenurus cerebralis) is the causative agent of coenurosis, a disease affecting the health of herbivores, resulting in great economic loss to animal husbandry. Heat-shock proteins (HSPs), expressed in all prokaryotes and eukaryotes, act as molecular chaperones and can affect pathogenicity. Methods Herein, cDNAs of T. multiceps genes Tm-HSP60 and Tm-p36 were cloned and molecularly characterised by bioinformatics analyses. The immunogenicity and immunoreactivity of recombinant rTm-HSP60 and rTm-p36 proteins were investigated by immunoblotting and indirect ELISA was established to evaluate their serodiagnostic potential. Tissue localisation and transcriptional level at different life stages of T. multiceps were determined by immunohistochemical and quantitative real-time PCR analyses. Result The 533 residue rTm-HSP60 and the 314 residue rTm-p36 proteins share typical highly conserved features of HSPs. Tm-p36 shares structural characteristics with metazoan small HSPs, with two N-terminal α-crystallin domains. Compared with Tm-p36, Tm-HSP60 displayed stronger immunogenicity, and the indirect ELISA based on rTm-HSP60 exhibited a sensitivity of 83.3% and a specificity of 87.5%, while rTm-p36 was not suitable to develop indirect ELISA. Tm-HSP60 was widely distributed in all stages of T. multiceps, albeit at relatively low levels, while Tm-p36 was specifically distributed in the protoscolex and oncosphere. Conclusions The sequence, structural and functional analyses of these two HSPs indicates that they may play important roles in the life-cycle of T. multiceps as molecular chaperones. Tm-HSP60 displayed stronger immunogenicity compare to Tm-p36, and has the potential for antibody detection. Tm-p36 was strongly associated with the activation of oncospheres and has potential interest for vaccination.

Urocystis prolifer Villot, 1880 is an intestinal parasite of Sorex spp. In the Palaearctic. There are significant differences in the descriptions of both adults and stages of ontogenesis of U. prolifer as described by various authors. The experimental infection of intermediate hosts with cestodes has been conducted. An overview of the geographical distribution, infestation of the definitive hosts and the development of the metacestode stages of U. prolifer are presented. The cestode is characterized by an extensive geographic area in the Palaearctic, wide host specificity and very high rates of infection of its definitive host. Urocystis prolifer has been recorded mostly in the taiga and forest zones of Palaearctic. Fourteen species of Sorex were registered as the definitive host. Redescription of U. prolifer and an amended generic diagnosis are provided. A complete description of the ontogeny from oncosphere to fully developed metacestode is given. Features of development of the metacestode are an asexual larval reproduction, the absence of the anterior and posterior obturator valve in the cyst of the fully developed urocyst, as well as excretory bodies. [ABSTRACT FROM AUTHOR]

Hydatigera taeniaeformis (H. taeniaeformis) is one of the most robust of tapeworm parasites that is widely distributed around the world. Information of proteins of H. taeniaeformis has not previously been reported. Using liquid chromatography tandem-mass spectrometry (LC–MS/MS) analysis, the proteome of H. taeniaeformis metacestode was profiled and a total of 408 proteins were identified. Of these, 26.5% (108/408) were annotated to be associated with metabolic pathways. Consistently, Gene Ontology analysis showed that those identified proteins were mainly classified into metabolic process of the biological processes. A set of metabolic enzymes, including Fructose-1,6-bisphosphate aldolase, enolase, Glucan phosphorylase, and phosphoenolpyruvate carboxykinase, were abundant in H. taeniaeformis metacestodes. In addition, some rare but interesting proteins like antigens (such as tegument protein and Antigen B) were identified. The two recombinant proteins of tegument protein and Antigen B were well-recognized by the sera from the H. taeniaeformis-infected mice. The H. taeniaeformis metacestode proteome might help to find new candidates for the immunodiagnosis and vaccine development and provide valuable information on H. taeniaeformis biology.

The tapeworm Taenia crassiceps has an indirect life cycle. Occasionally, metacestode stages have been reported from aberrant hosts as dogs, cats, lemurs and humans. This study describes an unusual series of serious cysticercosis cases: an 18-month-old male Yorkshire terrier dog with pleural cysticercosis accompanied by a cough, a 10-year-old male Shih Tzu dog with subcutaneous cysticercosis as well as a Cape ground squirrel and a Senegal bushbaby, both with generalised cysticercosis. Surgery was successful only in the Shih Tzu. The Yorkshire terrier died a few hours after surgery, while the Cape ground squirrel was euthanised and the Senegal bushbaby died before surgery. Cysticerci from the four cases were identified morphologically and using molecular methods. Fragments of genes coding for cytochrome oxidase subunit 1 were sequenced for each of the four isolates. Their affiliation to T. crassiceps was confirmed by comparison with the sequence data of other isolates available in the GenBank database. In general, the comparison of sequences of all isolates showed low variability in nucleotide composition (at most five positions). The cases from captive zoo animals represent the first findings of T. crassiceps in the Cape ground squirrel and Senegal bushbaby. The optimal treatment of cysticercosis caused by T. crassiceps remains unclear. Successful attempts usually include extensive surgical interventions and prolonged anthelmintic treatment. Chemotherapeutic options are limited. Although regular deworming targeting intestinal helminths of dogs is not effective against T. crassiceps cysticerci, it may help to prevent contamination of the environment by tapeworm eggs contained in dog faeces and reduce the risk of infection for susceptible animals and humans.

Background: This study focused on the monitoring of patients who had undergone liver transplantation (LT) because of unresectable alveolar echinococcosis (AE). The role of long‐term administration of albendazole (ABZ) in patients with residual/recurrent AE lesions and without AE lesions was evaluated. Methods: Albendazole therapy was prescribed to patients diagnosed with AE 4‐6 weeks after LT on the background of continuous suppressive therapy while following the protocol for managing patients after LT. Clinical data (general condition, blood counts, and level of hepatic transaminases), ultrasound scans (USs), magnetic resonance imaging (MRI) or multispiral computed tomography (MSCT), and serological data were collected from four patients with residual/recurrent AE lesions and without AE lesions. The results of the USs, MRI, and MSCT examinations at diagnosis and at the end of follow‐up were retrospectively reviewed for all patients. Results: Observation of patients over a long period (up to 10 years) showed that the continuous (without interruption) use of ABZ restrained the development of metacestodes. Interruptions in taking the drug, associated with the manifestation of hepatotoxicity in some patients, led to the development of lesions in other organs in which the parasite had not previously been detected. No new foci were found in the transplanted livers of the patients. Conclusion: Liver transplantation, together with continuous anti‐relapse chemotherapy, prolongs the patient's life, both in the absence and in the presence of metastases in other organs. [ABSTRACT FROM AUTHOR]

The current chemotherapeutical treatment against alveolar echinococcosis relies exclusively on benzimidazoles, which are not parasiticidal and can induce severe toxicity. There are no alternative treatment options. To identify novel drugs with activity against Echinococcus multilocularis metacestodes, researchers have studied potentially interesting drug targets (e.g. the parasite's energy metabolism), and/or adopted drug repurposing approaches by undertaking whole organism screenings. We here focus on drug screening approaches, which utilize an in vitro screening cascade that includes assessment of the drug-induced physical damage of metacestodes, the impact on metacestode viability and the viability of isolated parasite stem cells, structure-activity relationship (SAR) analysis of compound derivatives, and the mode of action. Finally, once in vitro data are indicative for a therapeutic window, the efficacy of selected compounds is assessed in experimentally infected mice. Using this screening cascade, we found that the anti-malarial mefloquine was active against E. multilocularis metacestodes in vitro and in vivo. To shed more light into the mode of action of mefloquine, SAR analysis on mefloquine analogues was performed. E. multilocularis ferritin was identified as a mefloquine-binding protein, but its precise role as a drug target remains to be elucidated. In mice that were infected either intraperitoneally with metacestodes or orally with eggs, oral treatment with mefloquine led to a significant reduction of parasite growth compared to the standard treatment with albendazole. However, mefloquine was not acting parasiticidally. Assessment of mefloquine plasma concentrations in treated mice showed that levels were reached which are close to serum concentrations that are achieved in humans during long-term malaria prophylaxis. Mefloquine might be applied in human AE patients as a salvage treatment. Future studies should focus on other repurposed anti-infective compounds (MMV665807, niclosamide, atovaquone), which showed stronger in vitro activity against E. multilocularis than mefloquine. Image 1 • Anti-infective drugs are repurposed for identification of novel drugs against AE. • Mefloquine is active against E. multilocularis in vitro and in mice. • The energy metabolism of E. multilocularis is a target for future drug development. • MMV665807 and niclosamide are highly active against E. multilocularis in vitro. [ABSTRACT FROM AUTHOR]

Appropriate medical management can be an alternative in those patients with submacular cysticercosis in whom achieving good visual outcome with vitreoretinal surgery is not possible. We report the case of a 25-year-old female who presented complaining of blurred vision in her left eye associated with photopsias and metamorphopsias of 3 months duration. Initial visual acuity in the right eye was 20/20 and 20/100 in the left eye. Upon indirect ophthalmoscopy in the left eye, a yellow-white, dome-shaped, elevated lesion with foveal involvement was observed. The rest of the ophthalmological examination proved normal. With clinical findings and images, submacular cysticercosis was diagnosed, and vitreoretinal surgery was suggested. Nevertheless, the patient did not accept the treatment; therefore, medical management was initiated. Central nervous system involvement was ruled out, and treatment with praziquantel and systemic prednisolone was initiated. Cysticercosis was resolved with significant improvement of her symptoms and visual acuity. [ABSTRACT FROM AUTHOR]

Abstract Background Radiotherapy may represent an alternative treatment modality for cystic echinococcosis (CE), but there is no adequate evidence for it up to now. In this study, we aim to investigate the parasiticidal effects of X-ray on the metacestodes of Echinococcus granulosus in vitro. Methods Protoscoleces obtained from sheep naturally infected with CE were cultivated in RPMI 1640 medium containing 10% fetal bovine serum (FBS) at 37 °C in 5% CO2. Upon encystation on day 14, the metacestodes were subjected to various intensities of X-ray. Metacestode structures were observed using light microscope and transmission electron microscopy (TEM), and Real-Time PCR was carried out to determine the expression of EgTPX, EgHSP70, EgEPC1 and Caspase-3. Results On day 14, encystation was noticed in the majority of protoscoleces in the control group. In the X-ray groups, the encystation rate showed significant decrease compared with that of the control group (P

In recent parasitological surveys performed on the Peruvian scallop, Argopecten purpuratus, from bottom cultures of Sechura Bay, Piura, Peru, free and encysted metacestodes were frequently found in their gonads. The objective of this study was to identify this metacestode, determine their prevalence and intensity and briefly assess the histopathological impact in the affected tissues. A parasitological study of 890 scallops over a 3-year period was performed in order to determine the parasite prevalence and intensity. Microscopical observation of details of the scolex and histopathological study of the affected host tissues were performed as well as molecular characterization of the parasite based on 18S and 28S rDNA sequences. The prevalence of the metacestode was 82.2% in August of 2013, 90.4% in November of 2014, and 83.1% and 85.6% in April and September of 2015, respectively. The highest average intensity (218.4) was found in spring of 2014. The histopathological study showed that plerocercoids reduced the gonadal space where the ovules develop. The molecular characterization and phylogenetic analysis revealed that the metacestodes belong to the genus Caulobothrium having high sequence similarity to Caulobothrium opisthorchis. This study constitutes the first report of Caulobothrium metacestodes in the scallop A. purpuratus. [ABSTRACT FROM AUTHOR]

• Antigen B (AgB) and thioredoxin peroxidase (TPx) from Taenia multiceps were cloned. • The antigens were evaluated as agents for serological diagnosis of coenurosis. • Tm-AgB shows high sensitivity and thermal stability. • Tm-AgB is an excellent candidate antigen for coenurosis diagnosis kits. Coenurosis is a serious parasitic disease of herbivorous animals caused by the metacestode of Taenia multiceps (Coenurus cerebralis). Accordingly, a significant amount of research is currently dedicated to the development of appropriate antigens for use in rapid and accurate coenurosis diagnosis kits. In the present study, antigen B (AgB) and thioredoxin peroxidase (TPx) from T. multiceps were cloned and expressed using a prokaryotic system, molecular characterization of Tm -AgB was determined by bioinformatical analyses. The serological diagnostic potentials of r Tm -AgB and r Tm -TPx were evaluated by indirect ELISA and compared with those of previously reported r Tm -AnxB2, r Tm -HSP70, and r Tm -GST. The results showed that Tm -AgB is a specific lipoprotein of cestodes with good thermal stability. The ELISA assay showed that r Tm -AgB exhibited a sensitivity of 95.8% and a specificity of 87.5%, indicating its strong potential for serological diagnosis of T. multiceps. [ABSTRACT FROM AUTHOR]

Abstract Mesocestoides spp. are tapeworms harbored in the intestine of many domestic and wild carnivores, birds of prey and, rarely, of humans. The life cycle is assumed to involve three hosts and the metacestode juvenile stage (tetrathyridium) may reproduce asexually, provoking severe systemic infections. In the present study, a case of a peritoneal infection by Mesocestoides sp. occurred in a captive gold-handed tamarin (Saguinus midas) is described. Phylogenetic positions based on CO1 and 12S loci were analysed to describe in details this unusual finding of Mesocestoides in a callitrichid monkey. The phylogenetic analyses has not clearly resolve relationships between the metacestode forms from the tamarin and any of the described Mesocestoides species available so far, including those described from non-human primates, thus supporting the hypothesis of a new taxon within the genus. Graphical abstract Unlabelled Image Highlights • Mesocestoides sp. is recovered for the first time from captive Saguinus midas. • Results suggest the existence of a new taxon within the genus Mesocestoides. • The phylogenetic analyses confirm the validity of distinct clades within the genus. [ABSTRACT FROM AUTHOR]

Echinococcus multilocularis transmission predominantly occurs in Europe between the red fox (Vulpes vulpes) and various species of rodent intermediate hosts. We infected 3 species of rodent, Myodes glareolus (n = 47), Mesocricetus auratus (n = 11) and outbred Mus musculus (CD-1 IGS) (n = 9) with an E. multilocularis egg suspension that contained 100 eggs with viable oncospheres and performed post mortem examination 6, 8 (M. glareolus) and 10 weeks post inoculation (wpi). C57BL/6j mice (n = 4) were used as positive controls as they have been shown to exhibit macroscopic liver lesions 4 wpi. To the best of our knowledge, this is the first study to experimentally assess susceptibility in the ostensibly competent host M. glareolus. Lesions were only detected in 2 of 47 M. glareolus (4.3%) at 8 and 10 wpi and although both contained protoscolices (1675 at 8 wpi and 88 at 12 wpi) the low percentage of infected animals brings into question their role as transmitters of the parasite. Significant differences were observed between inbred and outbred mice with E. multilocularis infection in the former demonstrating increased establishment (p ≤ 0.0001) and growth (p ≤ 0.0001). No lesions were found in all 11 M. auratus.

We previously reported fatal infection of a captive Bornean orangutan with metacestodes of a novel taeniid tapeworm, Versteria sp. New data implicate mustelids as definitive hosts of these tapeworms in North America. At least 2 parasite genetic lineages circulate in North America, representing separate introductions from Eurasia.

This study determined the profile of proteins in T. hydatigena metacestode by LC-MS/MS. Furthermore, comparison of 6 tapeworms revealed the presence of Taenia-specific filamin proteins and Echinococcus-specific UGPase proteins. These data provide clues for better understanding of T. hydatigena biological characteristics, which provides a new choice for screening of new diagnostic antigens for differential diagnosis of diseases by coinfections of various tapeworm metacestodes. [ABSTRACT FROM AUTHOR]

The existence of cryptic species in the genus Hydatigera , cyclophillid cestodes, mainly of felids, was recently described based on molecular studies of parasites from Asia, Europe and Africa. However, the occurrence of H. taeniaeformis sensu stricto (s.s.), the species more widely distributed and with a presumed specificity for murid rodents as intermediate hosts, has not been formally described in Americas. In the present study, during necropsy of an Ingram's squirrel specimen, Guerlinguetus ingrami , found dead in the municipality of Belo Horizonte, Minas Gerais state, Brazil, strobilocerci were found in the liver. The metacestodes were subjected to morphological and molecular studies. Sequences of the COI barcode region were obtained and used for phylogenetic analyses. The morphology and measures of the rostellar hooks were compatible with the ones described for H. taeniaeformis s.s. This identification was confirmed by a molecular phylogenetic approach (96.2–99.7% similarity with isolates of the parasite from Europe and Asia). This is the first molecular confirmation of the existence of H. taeniaeformis s.s. on the American continent. Moreover, the involvement of sciurid rodents in the transmission of H. taeniaeformis s.s. is discussed here as a probable case of parasite spillover. [ABSTRACT FROM AUTHOR]

The tapeworm Taenia crassiceps has an indirect life cycle. Occasionally, metacestode stages have been reported from aberrant hosts as dogs, cats, lemurs and humans. This study describes an unusual series of serious cysticercosis cases: an 18-month-old male Yorkshire terrier dog with pleural cysticercosis accompanied by a cough, a 10-year-old male Shih Tzu dog with subcutaneous cysticercosis as well as a Cape ground squirrel and a Senegal bushbaby, both with generalised cysticercosis. Surgery was successful only in the Shih Tzu. The Yorkshire terrier died a few hours after surgery, while the Cape ground squirrel was euthanised and the Senegal bushbaby died before surgery. Cysticerci from the four cases were identified morphologically and using molecular methods. Fragments of genes coding for cytochrome oxidase subunit 1 were sequenced for each of the four isolates. Their affiliation to T. crassiceps was confirmed by comparison with the sequence data of other isolates available in the GenBank database. In general, the comparison of sequences of all isolates showed low variability in nucleotide composition (at most five positions). The cases from captive zoo animals represent the first findings of T. crassiceps in the Cape ground squirrel and Senegal bushbaby. The optimal treatment of cysticercosis caused by T. crassiceps remains unclear. Successful attempts usually include extensive surgical interventions and prolonged anthelmintic treatment. Chemotherapeutic options are limited. Although regular deworming targeting intestinal helminths of dogs is not effective against T. crassiceps cysticerci, it may help to prevent contamination of the environment by tapeworm eggs contained in dog faeces and reduce the risk of infection for susceptible animals and humans. [ABSTRACT FROM AUTHOR]

The metacestode stage of Taenia hydatigena has been described in wild and domestic ruminants, swine and equines. This larval cestode infection has economical importance due to its high pathogenicity in animals bred for human consumption. The socioeconomic impact of this infection is unknown in Venezuela. We report in this note the finding of a cyst structure, typical of the metacestode of T. hydatigena in a rural pig from Yaracuy state of Venezuela. The cyst was approximately 2.5 cm x 1.0 cm, with an interior scolex and a transparent cyst fluid. The serum of this animal was positive for the detection by ELISA of the specific antigen HP10 of Taenia sp. Further studies are needed to determine the endemicity of T. hydatigena in pigs and in other animal species in Venezuela as the high serological cross reaction between T. hydatigena and T solium, could cause confusion in the diagnosis of the considerably more economically important T. solium porcine cysticercosis. [ABSTRACT FROM AUTHOR]

Taenia hydatigena is a parasitic flatworm that is widely distributed around the world. Using MS/MS, the proteome of T. hydatigena cyst fluid (CF) was profiled and a total of 520 proteins were identified, 430 of which were of sheep origin. T. hydatigena shared 37 parasite-origin and 109 host-origin CF proteins with Echinococcus granulosus . Compared with E. granulosus , T. hydatigena had much more CF proteins associated with amino acid synthesis and complement cascades. In addition, glutamate metabolism and anti-oxidative reactions were identified as relatively more important events. These results suggest that T. hydatigena metacestodes have internal microenvironment with special immune and oxidative conditions. [ABSTRACT FROM AUTHOR]

A captive juvenile Bornean orangutan (Pongo pygmaeus) died from an unknown disseminated parasitic infection. Deep sequencing of DNA from infected tissues, followed by gene-specific PCR and sequencing, revealed a divergent species within the newly proposed genus Versteria (Cestoda: Taeniidae). Versteria may represent a previously unrecognized risk to primate health.

Alveolar echinococcosis (AE) is a worldwide zoonosis caused by E. multilocularis . Humans become infected through oral ingestion of the eggs. Host of E. multilocularis produces immune responses that help to either reject and/or limit the growth of this parasite, and in response the parasite produces molecules against this immune attack. This study identifies candidate key molecules in the early infection phase and the chronic stage of the parasite infestation, through comparison of gene expression of 4- and 16-week metacestodes. First, RNA was isolated from 4- and 16-weeks metacestodes of E. multilocularis (Nemuro strain). Thereafter, clean reads with lengths of 50 bp or longer were compared against a reference genome using TopHat. Functional annotation of transcripts of E. multilocularis were investigated using multi-step bioinformatics tools. At the gene ontology (GO) level, 356 and 1774 transmembrane (TM) predicted proteins of the E. multilocularis were mapped to an enhanced ‘hydrolase activity’ and increased ‘transmembrane transporter activity’, respectively. In addition, comparison of gene expression level between 4- and 16-week metacestode revealed 168 different expression (DE) genes. This study has demonstrated that, the expression levels of predicted ES and TM proteins in E. multilocularis change in the transformation from one stage to another. Genes that are highly expressed in immature or mature metacestode could be explored as novel candidates for diagnostic antigens and vaccine targets. [ABSTRACT FROM AUTHOR]

Cestodes (tapeworms) have complex adaptations to their obligatory parasitic life-style. Among these adaptations, they show many evolutionary innovations in their development, including complex life-cycles with multiple hosts and life-stages, several independent origins of asexual reproduction, and the evolution of segmentation as a mean to generate massive reproductive output. Therefore, cestodes offer many opportunities for the investigation of the evolutionary origins of developmental novelties (evo-devo). However, cestodes have not been exploited as major models for evo-devo research due to the considerable technical difficulties involved in their study. In this review, a panoramic view is given of classical aspects, methods and hypothesis of cestode development, together with recent advances in phylogenetics, genomics, culture methods, and comparative analysis of cestode gene expression. Together with the availability of powerful models for related free-living flatworms, these developments should encourage the incorporation of these fascinating parasites into the first-line of evo-devo research. [ABSTRACT FROM AUTHOR]

Taenia ovis metacestodes reside in the muscle of sheep and goats, and may cause great economic loss due to condemnation of carcasses if not effectively controlled. Although advances have been made in the control of T. ovis infection, our knowledge of T. ovis biology is limited. Herein the protein profiling of T. ovis metacestodes was determined by liquid chromatography-linked tandem mass spectrometry. A total of 966 proteins were identified and 25.1% (188/748) were annotated to be associated with metabolic pathways. Consistently, GO analysis returned a metabolic process (16.27%) as one of two main biological process terms. Moreover, it was found that 24 proteins, including very low-density lipoprotein receptor, enolase, paramyosin and endophilin B1, were abundant in T. ovis metacestodes. These proteins may be associated with motility, metabolism, signaling, stress, drug resistance and immune responses. Furthermore, comparative analysis of 5 cestodes revealed the presence of Taenia -specific enolases. These data provide clues for better understanding of T. ovis biology, which is informative for effective control of infection. [ABSTRACT FROM AUTHOR]

Two putative serpin genes were identified in Echinococcus multilocularis , in addition to the already reported serpinEmu , and were designated as serpin2Emu and serpin3Emu . Western blot analysis using polyclonal antibodies against serpinEmu, putative serpin2Emu protein, and putative serpin3Emu protein indicated that all three proteins were localized in both intracellular and excretory-secretory (ES) fractions of E. multilocularis metacestodes. In addition, immune staining of parasite tissue indicated that all three proteins were localized at the germinal layer. [ABSTRACT FROM AUTHOR]

A patient in Pennsylvania, USA, with common variable immunodeficiency sought care for fever, cough, and abdominal pain. Imaging revealed lesions involving multiple organs. Liver resection demonstrated necrotizing granulomas, recognizable tegument, and calcareous corpuscles indicative of an invasive cestode infection. Sequencing revealed 98% identity to a Versteria species of cestode found in mink. [ABSTRACT FROM AUTHOR]