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Background: Plerocercoid larvae of the tapeworm Spirometra mansoni can infect both humans and animals, leading to severe parasitic zoonosis worldwide. Despite ongoing research efforts, our understanding of the developmental process of S. mansoni remains inadequate. To better characterize posttranslational regulation associated with parasite growth, development, and reproduction, a comparative phosphoproteomic study was conducted on the plerocercoid and adult stages of S. mansoni., Methods: In this study, site-specific phosphoproteomic analysis was conducted via 4D label-free quantitative analysis technology to obtain primary information about the overall phosphorylation status of plerocercoids and adults., Results: A total of 778 differentially abundant proteins (DAPs) were detected between adults and plerocercoids, of which 704 DAPs were upregulated and only 74 were downregulated. DAPs involved in metabolic activity were upregulated in plerocercoid larvae compared with adults, whereas DAPs associated with binding were upregulated in adults. Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analyses indicated that most DAPs involved in signal transduction and environmental information processing pathways were highly active in adults. DAPs upregulated in the plerocercoid group were enriched mainly in metabolic activities. The kinases PKACA, GSK3B, and smMLCK closely interact, suggesting potential active roles in the growth and development of S. mansoni., Conclusions: The dataset presented in this study offers a valuable resource for forthcoming research on signaling pathways as well as new insights into functional studies on the molecular mechanisms of S. mansoni., (© 2024. The Author(s).)

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 ., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The plerocercoid larvae of Spirometra mansoni are etiological agents of human and animal sparganosis. Annexins are proteins with important roles in parasites. However, our knowledge of annexins in S. mansoni is still inadequate. In this study, 18 new members of the Annexin (ANX) family were characterized in S. mansoni. The clustering analysis demonstrated that all the SmANXs were divided into two main classes, consistent with the patterns of conserved motif organization. The 18 SmANXs were detected at all developmental stages (plerocercoid, adult, and egg) and displayed ubiquitous but highly variable expression patterns in all tissues/organs studied. The representative member rSmANX18 was successfully cloned and expressed. The protein was immunolocalized in the tegument and parenchyma of the plerocercoid and in the tegument, parenchyma, uterus and egg shell of adult worms. The recombinant protein can bind phospholipids with high affinity in a Ca 2+ -dependent manner, shows high anticoagulant activity and combines with FITC to recognize apoptotic cells. Annexin gene polymorphism and conservative core motif permutation were found in both cestodes and trematodes. SmANXs also revealed high genetic diversity among Platyhelminthes of medical interest. Our findings lay a foundation for further studies on the biological functions of ANXs in S. mansoni as well as other taxa in which ANXs occur., (© X.Y. Su et al., published by EDP Sciences, 2024.)

Background: Spirometra mansoni can parasitize animals and humans through food and water, causing parasitic zoonosis. Knowledge of the developmental process of S. mansoni is crucial for effective treatment; thus, it is important to characterize differential and specific proteins and pathways associated with parasite development., Methods: In this study, we performed a comparative proteomic analysis of the plerocercoid and adult stages using a tandem mass tag-based quantitative proteomic approach. Additionally, integrated transcriptomic and proteomic analyses were conducted to obtain the full protein expression profiles of different life cycle stages of the tapeworm., Results: Approximately 1166 differentially expressed proteins (DEPs) were identified in adults versus plerocercoids, of which 641 DEPs were upregulated and 525 were downregulated. Gene Ontology (GO), Clusters of Orthologous groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that most DEPs related to genetic information processing and metabolism of energy in adults seem to be more activated. In the plerocercoid stage, compared to metabolism, genetic information processing appears more dynamic. Protein-protein interaction (PPI) revealed six key proteins (phosphomannomutase, glutathione transferase, malate dehydrogenase, cytoplasmic, 40S ribosomal protein S15, ribosomal protein L15 and 60S acidic ribosomal protein P2) that may play active roles in the growth and development of S. mansoni. Finally, the combination of transcriptomic and proteomic data suggested that three pathways (ubiquitin-mediated proteolysis, phagosome and spliceosome) and five proteins closely related to these pathways might have a significant influence in S. mansoni., Conclusions: These findings contribute to increasing the knowledge on the protein expression profiles of S. mansoni and provide new insights into functional studies on the molecular mechanisms of the neglected medical tapeworm., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Parasitic helminths modify host immune reactions to promote long-term parasitism. We previously purified a glycoprotein, plerocercoid-immunosuppressive factor (P-ISF), from the excretory/secretory products of Spirometra erinaceieuropaei plerocercoids and reported its cDNA and genomic DNA sequences. In this study, we isolated extracellular vesicles (EVs) from the excretory/secretory products of S. erinaceieuropaei plerocercoids and found that they suppressed the production of nitric oxide and the gene expression of tumor necrosis factor-α, interleukin-1β, and interleukin-6 in lipopolysaccharide-stimulated macrophages. EVs are membrane-bound vesicles 50-250 nm in diameter and are localized in the whole bodies of plerocercoids. EVs from plerocercoids encapsulate a variety of unidentified proteins and microRNAs (miRNAs), which are non-coding RNAs that play essential roles in post-transcriptional gene regulation. The miRNAs of the EVs were analyzed, and 334,137 sequencing reads were mapped to the genomes of other organisms. A total of 26 different miRNA families were identified, including miR-71, miR-10-5p, miR-223, and let-7-5p, which have been reported to have immunosuppressive effects. We confirmed that P-ISF was present in the supernatant but not in the EVs by western blotting with an anti-P-ISF antibody. These results suggest that S. erinaceieuropaei plerocercoids suppress host immunity by releasing P-ISF and EVs., Competing Interests: Declaration of Competing Interest All authors have declared no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Morphological characteristics and DNA sequencing were used to identify plerocercoids of a Schistocephalus sp. infecting slimy sculpin (Cottus cognatus) from northern New Brunswick and plerocercoids of Ligula intestinalis infecting blacknose dace (Rhinichthys atratulus) in Fundy National Park (FNP, New Brunswick). To our knowledge, no previous publications documented either cestode from New Brunswick, Canada. Blacknose dace represent a new host record for L. intestinalis. Identifications were made based on the presence or absence of segmentation and sequencing partial nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1; mitochondrial DNA) and/or partial cytochrome c oxidase subunit 1 (COI; mitochondrial DNA). Plerocercoids from blacknose dace in FNP were identified as Ligula intestinalis based on >99% nucleotide identity with COI for this species in the NCBI GenBank database. Plerocercoids in slimy sculpin from northern New Brunswick were identified as a Schistocephalus sp. based on high nucleotide identity with congenerics in the NCBI GenBank database. The absence of GenBank entries with sufficient high percent identity to our specimens, and potential species hybrids in this genus, prevents species-level identification of Schistocephalus sp. plerocercoids currently. The absence of previous documentation of these cestodes might reflect recent environmental change promoting the transmission of these parasites that can modulate host fish behavior, induce sterility of host fishes, and contribute to epizootics., (© American Society of Parasitologists 2023.)

We report a case of Spirometra infection in a Samar cobra ( Naja samarensis ) imported from the Philippines, belonging to a zoological collection in the southern United States. Under a poor post-surgical prognosis, the snake was euthanized, and at necropsy plerocercoids of a Diphyllobotriidea were found in its subcutaneous tissues and musculature. Molecular and phylogenetic analyses of the complete cytochrome oxidase c subunit I ( cox1 ) gene of the mitochondrial DNA confirmed that the isolate belonged to the genus Spirometra and was closely related to Spirometra mansoni isolates from Asian countries (bootstrap support = 99.4%). Considering the origin and clinical history and handling of the animal, the snake probably arrived infected in America. We suggest the inclusion of diagnostic imaging in the investigation of sparganosis in research and disease surveillance protocols applied in the pre- and post-quarantine period to asymptomatic animals imported from endemic areas., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors.)

The mitochondria of adult and plerocercoid Spirometra mansoni were characterized in isolated mitochondria and in situ by electron microscopic histochemistry with special attention to the respiratory chain. Although the specific activities of the constituent enzyme complexes of succinate oxidase are fairly similar in adult and plerocercoid mitochondria, those of succinate oxidase and NADH-FRD are approximately 4- and 25-fold higher in adult mitochondria than in plerocercoid mitochondria, respectively. Quinone analysis by high performance liquid chromatography and mass spectrometry showed that adult and plerocercoid mitochondria contained both rhodoquinone-10 and ubiquinone-10 at concentrations of 4.98 and 0.106 nmol mg -1 for adult, and 0.677 and 0.137 nmol mg -1 for plerocercoid, respectively. Inhibition studies on the succinate-oxidase system of adult mitochondria showed that they possessed both cyanide-sensitive and -insensitive succinate oxidases, the latter of which produces hydrogen peroxide. Adult mitochondria, when NADH was used as a substrate, were shown to produce hydrogen peroxide, and the production of hydrogen peroxide decreased to undetectable levels in the presence of fumarate. The specific activities of NADH-fumarate reductase and cytochrome c oxidase were significantly higher in mature proglottids than in immature and gravid proglottids. Isopycnic density-gradient centrifugation analyses and in situ electron microscopic histochemistry revealed that both adult and plerocercoid mitochondria were heterogeneous in terms of respiratory function and physicochemical properties. The physiological significance of adult and plerocercoid mitochondria is discussed in relation to the oxygen tension of their parasitic habitats., Competing Interests: Declaration of Competing Interest The authors declare that no conflict of interest exists., (Copyright © 2022. Published by Elsevier B.V.)

Background: In China, the plerocercoid of the cestode Spirometra mansoni is the main causative agent of human and animal sparganosis. However, the population genetic structure of this parasite remains unclear. In this study, we genotyped S. mansoni isolates with the aim to improve current knowledge on the evolution and population diversity of this cestode., Methods: We first screened 34 perfect simple sequence repeats (SSRs) using all available omic data and then constructed target sequencing technology (Target SSR-seq) based on the Illumina NovaSeq platform. Next, a series of STRUCTURE. clustering, principal component, analysis of molecular variance and TreeMix analyses were performed on 362 worm samples isolated from 12 different hosts in 16 geographical populations of China to identify the genetic structure., Results: A total of 170 alleles were detected. The whole population could be organized and was found to be derived from the admixture of two ancestral clusters. TreeMix analysis hinted that possible gene flow occurred from Guizhou (GZ) to Sichuan (SC), SC to Jaingxi (JX), SC to Hubei (HB), GZ to Yunnan (YN) and GZ to Jiangsu (JS). Both neighbor-joining clustering and principal coordinate analysis showed that isolates from intermediate hosts tend to cluster together, while parasites from definitive hosts revealed greater genetic differences. Generally, a S. mansoni population was observed to harbor high genetic diversity, moderate genetic differentiation and a little genetic exchange among geographical populations., Conclusions: A Target SSR-seq genotyping method was successfully developed, and an in-depth view of genetic diversity and genetic relationship will have important implications for the prevention and control of sparganosis., (© 2022. The Author(s).)

The plerocercoid larvae of the tapeworm Spirometra erinaceieuropaei can parasitize humans and animals and cause serious parasitic zoonosis. However, our knowledge of the developmental process of S. erinaceieuropaei is still inadequate. To better characterize differential and specific genes and pathways associated with parasite development, a comparative transcriptomic analysis of the plerocercoid stage and the adult stage was performed using RNA-seq and de novo analysis. Approximately 13,659 differentially expressed genes (DEGs) were identified in plerocercoids versus adults, of which 6455 DEGs were upregulated and 7204 were downregulated. DEGs involved in parasite immunoevasion were more active in plerocercoid larvae than in adults, while DEGs associated with metabolic activity were upregulated in adults. Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analyses revealed that most DEGs involved in protein phosphorylation/dephosphorylation and the Wnt signalling pathway were much more active in plerocercoid larvae. The molecular functions of upregulated unigenes in adults were mainly enriched for metabolic activities. qPCR validated that the expression levels of 10 selected DEGs were consistent with those in RNA-seq, confirming the accuracy of the RNA-seq results. Our results contributed to increasing the knowledge on the S. erinaceieuropaei gene repertoire and expression profile and also provide valuable resources for functional studies on the molecular mechanisms of S. erinaceieuropaei., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Human sparganosis is a food-borne parasitic disease caused by the plerocercoids of Spirometra species. Clinical diagnosis of sparganosis is crucial for effective treatment, thus it is important to identify sensitive and specific antigens of plerocercoids. The aim of the current study was to identify and characterize the immunogenic proteins of Spirometra erinaceieuropaei plerocercoids that were recognized by patient sera. Crude soluble extract of the plerocercoids were separated using 2-dimensional gel electrophoresis coupled with immunoblot and mass spectrometry analysis. Based on immunoblotting patterns and mass spectrometry results, 8 antigenic proteins were identified from the plerocercoid. Among the proteins, cysteine protease protein might be developed as an antigen for diagnosis of sparganosis.

The protein composition of the cestode Schistocephalus solidus was measured in an experiment simulating the trophic transmission of the parasite from a cold-blooded to a warm-blooded host. The first hour of host colonisation was studied in a model experiment, in which sticklebacks Gasterosteus aculeatus infected with S. solidus were heated at 40°C for 1 h. As a result, a decrease in the content of one tegument protein was detected in the plerocercoids of S. solidus. Sexual maturation of the parasites was initiated in an experiment where S. solidus larvae were taken from fish and cultured in vitro at 40°C for 48 h. Temperature-independent changes in the parasite proteome were investigated by incubating plerocercoids at 22°C for 48 h in culture medium. Analysis of the proteome allowed us to distinguish the temperature-induced genes of S. solidus, as well as to specify the molecular markers of the plerocercoid and adult worms. The main conclusion of the study is that the key enzymes of long-term metabolic changes (glycogen consumption, protein production, etc.) in parasites during colonisation of a warm-blooded host are induced by temperature., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Oarfish (Regalecus russelii Cuvier) are mesopelagic fish with little known about their life history. Oarfish live in deep water, making it difficult for researchers to collect specimens; thus, records of their parasitic helminths are limited. Two plerocercoids were found for the first time in an oarfish stranded on the coast of Akita Prefecture, Japan. These plerocercoids were identified as Clistobothrium sp. RR-1 using morphological and molecular analyses. It was revealed that oarfish represent one of the intermediate hosts of the genus Clistobothrium, and large sharks are the definitive hosts for these parasites.

We report three cases of sparganosis due to plerocercoids of the tapeworm Spirometra sp. in captive meerkats ( Suricata suricatta ) from a zoo exhibit in the southeastern United States. Two meerkats were euthanized, one due to an uncontrollable seizure and the other due to trauma, and at necropsy cysts containing cestode larvae were observed. A third meerkat had a subcutaneous nodule surgically removed, which contained similar larvae. The third animal died years later, and had numerous cestode larvae in the pleural and peritoneal cavities. The larvae were morphologically identified as plerocercoids of diphyllobothriidean cestodes. On necropsy, multiple nodules, ranging in size from 2.5 to 3.0 cm, were observed in the subcutaneous tissue and muscles. Multifocally, separating skeletal muscle fibers were longitudinal and transversal sections of cestode larva. Histologically, parasitic cysts contained large numbers of neutrophils and macrophages, admixed with proteinaceous material. Molecular and phylogenetic analyses confirmed that specimens from one of the meerkats belonged to the genus Spirometra and was closely related to Spirometra plerocercoids isolated from a snake from the United States and wild felids from South America. Meerkats likely became infected by ingesting infected second intermediate hosts, such as amphibians and reptiles that may have entered the exhibit. Management practices that minimize access of meerkats and other susceptible hosts to intermediate hosts should be implemented., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 The Authors.)

A platyhelminth, Spirometra erinaceieuropaei, belonging to the class Cestoda, causes human sparganosis, and infection with its larva results in subtle inflammation in the body of its host. We previously reported the purification of a glycoprotein, plerocercoid-immunosuppressive factor (P-ISF) from the excretory/secretory products of S. erinaceieuropaei plerocercoids that may be involved in immuno-modification. We determined the sequence of P-ISF from the N-terminal and the internal 10 amino acids of P-ISF using degenerate PCR and 5'- and 3'-RACE methods. The putative gene encoding P-ISF was 1443 bp long and the gene contained 10 exons and 9 introns in a genomic DNA of size 5205 bp. P-ISF consists of 480 amino acids including the N-terminal signal peptide sequence, and has two unknown domains,-cestoda cysteine-rich domains (CCDs) and a fibronectin type III domain between the two CCDs. All cysteine residues were conserved in the two CCDs, which shared 62% amino acid identities. Homologous analysis revealed that the CCDs were homologous with an unknown protein of Diphyllobothrium latum. To produce specific antibodies, we expressed recombinant P-ISF (rP-ISF) using wheat germ protein synthetic system. P-ISF was localized in the sub-cutaneous tissues and the parenchymal tissues of plerocercoids. Transcription of P-ISF was detected only in plerocercoid stage, but not in adult stage. Western blotting also showed a band in plerocercoide stage but not in adult. The rP-ISF did not suppress nitrite production in RAW 264.7 cells stimulated with LPS, and this might be due to lack of carbohydrate chains in the recombinant protein., Competing Interests: Declaration of Competing Interest All authors have declared no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Diphyllobothriosis is a fish-borne parasitic zoonosis caused by so-called "broad tapeworms" or "fish tapeworms" of different genera of the order Diphyllobothriidea. Dibothriocephalus latus (Linnaeus 1758), (syn. Diphyllobothrium latum) , is a medically important type species of the genus, whose occurrence in various European regions is either regular, e.g. in the Alpine lakes region, or occasional and sporadic, e. g. in the Danube River region. For the latter, data on the detection of D. latus plerocercoids in the second intermediate fish host (European perch Perca fluviatilis ), as well as in definitive hosts (human and dog), in which infection was directly linked to the consumption of infected fish from the Danube, were published more than 50 years ago. In order to assess the current situation, we aimed to find out whether D. latus is present in the natural environment of the Danube River. In total, 700 perch from five sampling sites in the Slovak part of the Danube River were examined. Plerocercoids were not detected in any fish examined, which leads to the conclusion that D. latus is currently not present in the studied aquatic environment., Competing Interests: Conflict of interest Authors declare no conflict of interest., (© 2019 A. Radačovská, E. Bazsalovicsová, I. Králová-Hromadová, published by Sciendo.)

Sparganosis is a zoonosis caused by the spargana (larvae) of Spirometra sp. (Diphyllobothriidae). Reptiles are particularly important vectors for the transmission of this parasite in Asia; however, their role in sparganosis spread in European wildlife is unrecognized. We investigated the infection of reptiles with Spirometra sp. in NE Poland, where several mammalian hosts have been identified recently and in the past. Of the 59 dead reptiles, plerocercoids were found in two grass snakes (Natrix natrix) from the Białowieża Primeval Forest (BPF). The Spirometra erinaceieuropaei species was genetically confirmed using the evolutionary conserved nuclear 18S rRNA gene, and then compared to GenBank deposits. The sequences were identical to previously investigated Spirometra sp. found in Eurasian badger and wild boar from BPF. Our finding is the first genetically confirmed record of Spirometra sp. in reptiles in Europe. Since reptiles are often a component of mammalian diet, they can be a source of Spirometra tapeworm infection in European wildlife; however, further studies are needed to investigate the prevalence of infection in reptiles and other non-mammalian hosts.

Sparganosis in humans caused by the plerocercoid larvae of Spirometra erinaceieuropaei is found worldwide, especially in Eastern Asia and the Far East. Previous studies have suggested that dissolution of plerocercoid body, plerocercoid invasion of host tissue, and migration are important processes for sparganosis progression. However, the mechanisms underlying these processes have yet to be determined. Here, we demonstrated the enzymatic property and involvement of a native 23kDa cysteine protease (Se23kCP), purified from plerocercoids, in sparganosis pathogenesis. Se23kCP is mature protease consisting of 216 amino acids and has a high sequence similarity with cathepsin L in various organisms. Se23kCP conjugated with N-glycans, which have a core fucose residue. Both cysteine and serine protease-specific activities were determined in Se23kCP and their optimal pHs were found to be different, indicating that Se23kCP has a wide range of substrate specificity. Se23kCP was secreted from tegumental vacuoles of the plerocercoid to host subcutaneous tissues and degraded human structural proteins, such as collagen and fibronectin. In addition, the plerocercoid body was lysed by Se23kCP, which facilitated larval invasion of host tissue. Our findings suggest that Se23kCP induces host tissue invasion and migration, and might be an essential molecule for sparganosis onset and progression., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Diphyllobothriosis is reemerging because of global importation and increased popularity of eating raw fish. We detected Diphyllobothrium nihonkaiense plerocercoids in the musculature of wild pink salmon (Oncorhynchus gorbuscha) from Alaska, USA. Therefore, salmon from the American and Asian Pacific coasts and elsewhere pose potential dangers for persons who eat these fish raw.

From February to March 2016 we found plerocercoids of Spirometra sp. in four wild boar hunted in Białowieża Primeval Forest, north-eastern Poland. Plerocercoids were located subcutaneously and in muscle tissue. A sequence of a nuclear 18S rRNA gene was used for genetic specification of the samples. The analyzed gene fragment showed 100% identity with the Spirometra erinacei sequence. Thus, the emerge of human sparganosis due to consumption of undercooked or smoked wild boar meat is likely in the areas where wild boar is an approved food source, especially in the absence of routine guidelines for vets. It has become a priority to inform the public about possibilities and consequences of this zoonosis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

We describe here the mass death of predatory carp, Chanodichthys erythropterus, in Korea induced by plerocercoid larvae of Ligula intestinalis as a result of host manipulation. The carcasses of fish with ligulid larvae were first found in the river-edge areas of Chilgok-bo in Nakdong-gang (River), Korea at early February 2016. This ecological phenomena also occurred in the adjacent areas of 3 dams of Nakdong-gang, i.e., Gangjeong-bo, Dalseong-bo, and Hapcheon-Changnyeong-bo. Total 1,173 fish carcasses were collected from the 4 regions. To examine the cause of death, we captured 10 wondering carp in the river-edge areas of Hapcheon-Changnyeong-bo with a landing net. They were 24.0-28.5 cm in length and 147-257 g in weight, and had 2-11 plerocercoid larvae in the abdominal cavity. Their digestive organs were slender and empty, and reproductive organs were not observed at all. The plerocercoid larvae occupied almost all spaces of the abdominal cavity under the air bladders. The proportion of larvae per fish was 14.6-32.1% of body weight. The larvae were ivory-white, 21.5-63.0 cm long, and 6.0-13.8 g in weight. We suggest that the preference for the river-edge in infected fish during winter is a modified behavioral response by host manipulation of the tapeworm larvae. The life cycle of this tapeworm seems to be successfully continued as the infected fish can be easily eaten by avian definitive hosts.

Human sparganosis is a zoonotic disease caused by infection with larval forms (procercoid/plerocercoid) of Spirometra spp. The purpose of this study was to identify Spirometra spp. of infected snakes using a multiplex PCR assay and phylogenetic analysis of mitochondrial DNA sequence data from the spargana of terrestrial snakes obtained from Korea and China. A total of 283 snakes were obtained that included 4 species of Colubridae comprising Rhabdophis tigrinus tigrinus (n=150), Dinodon rufozonatum rufozonatum (n=64), Elaphe davidi (n=2), and Elaphe schrenkii (n=7), and 1 species of Viperidae, Agkistrodon saxatilis (n=60). The snakes were collected from the provinces of Chungbuk, Chungnam, and Gyeongbuk in Korea (n=161), and from China (n=122). The overall infection rate with spargana was 83% (235/283). The highest was recorded for D. rufozonatum rufozonatum (100%), followed by A. saxatilis (85%) and R. tigrinus tigrinus (80%), with a negative result for E. davidi (0%) and E. schrenkii (0%). The sequence identities between the spargana from snakes (n=50) and Spirometra erinaceieuropaei (KJ599680) or S. decipiens (KJ599679) control specimens were 90.8% and 99.2%, respectively. Pairwise genetic distances between spargana (n=50) and S. decipiens ranged from 0.0080 to 0.0107, while those between spargana and S. erinaceieuropaei ranged from 0.1070 to 0.1096. In this study, all of the 904 spargana analyzed were identified as S. decipiens either by a multiplex PCR assay (n=854) or mitochondrial cox1 sequence analysis (n=50).

A visceral helminth of the squid, Todarodes pacificus, is reported from the East Sea, the Republic of Korea. Total 39 squid samples were purchased from a fish market in Jumunjin-eup, Gangneung-si (City) from August 2014 to July 2015 and were examined for helminth parasites with naked eyes and under a stereomicroscope after opening the abdominal cavity with a pair of scissors. Whitish larval worms were mainly found in the stomach and abdominal cavity of the squid. They were detected in 25 (64.1%) out of 39 squids examined, and the infection density was 7 larvae per infected squid. Spatula-shaped larvae were 8.2×2.0 mm in average size, round to slightly flattened anteriorly, with round hatching posteriorly, and had characteristic 4 tentacles with numerous hooklets in the scolex. The larvae were identified as the plerocercoid stage of Nybelinia surmenicola by their morphological features. This finding represents a new host record and the first report of N. surmenicola infection in T. pacificus squids from the east coast of Korea.

The Spirometra erinacei casein kinase I (SeCKI) gene was cloned and expressed in Escherichia coli, and its characteristics were investigated in this study. The recombinant SeCP protein (rSeCKI) was purified. The vaccination of mice with rSeCKI induced the Th1/Th2-mixed type of immune response with Th2 predominant (high levels of IgG1). Western blotting analysis showed that rSeCP was recognized by the sera of plerocercoid-infected mice, and anti-rSeCP serum recognized the native SeCP protein of plerocercoid crude antigens. Transcription and expression of SeCP was observed at the plerocercoid and adult stages of S. erinacei. Immunolocalization identified SeCKI in the tegument and parenchymal tissues of plerocercoids and in the teguments of adults. SeCKI appeared to be essential indispensable for the S. erinacei development and survival in host, but its biological functions need to be further investigated.

Spirometra sp. is a diphyllobothriid cestode which reproduces mainly in cat-like carnivores and canids. Several animal species that are not definitive hosts function as paratenic hosts, in which plerocercoids migrate to other tissues causing sparganosis. In this paper we describe the first case of sparganosis (Spirometra sp.) in Eurasian badger (Meles meles). It was found in an adult female Eurasian badger killed on the road in the Białowieża Primeval Forest (north-eastern Poland) in April 2013. At necropsy, 128 complete and 40 fragments of plerocercoids (spargana) were found and were located subcutaneously, mainly on the hind legs and along the spine. The average length of spargana was 87±38mm. No adult Spirometra sp. tapeworms were found in the animal intestine, indicating that the investigated badger was a paratenic host for Spirometra sp. Analysis of 18S rRNA gene sequences combined with morphological examination confirmed affiliation of the concerned plerocercoids to genus Spirometra., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Sparganosis is caused by the invasion of Spirometra sparganum into various tissues/organs. Subcutaneous sparganosis can be diagnosed by biopsy, while visceral/cerebral sparganosis is not easy to be diagnosed. The diagnosis depends largely on the detection of specific anti-sparganum antibodies. The specificity of the ELISA could be increased by using S. mansoni sparganum excretory-secretory (ES) antigens, but it also had the cross-reactions with sera of patients with cysticercosis or paragonimiasis. The aim of this study was to identify early specific diagnostic antigens in S. mansoni sparganum ES proteins., Methods: The sparganum ES proteins were analyzed by two-dimensional electrophoresis (2-DE) and Western blot probed with early sera from infected mice at 14 days post-infection. The immunoreactive protein spots were characterized by MALDI-TOF/ TOF-MS., Results: A total of approximately 149 proteins spots were detected with isoelectric point (pI) varying from 3 to 7.5 and molecular weight from 20 to 115 kDa and seven protein spots with molecular weight of 23-31 kDa were recognized by the infection sera. Three of seven spots were successfully identified and characterized as the same S. mansoni protein (cysteine protease), and the proteins of other 4 spots were not included in the databases., Conclusion: The cysteine protease from S. mansoni ES proteins recognized by early infection sera might be the early diagnostic antigens for sparganosis.