Molecular identification of Spirometra infections in companion animals and wildlife in Japan

Spirometra infections in companion animals and wildlife in Japan have been diagnosed based on the morphology of the adult worms and eggs, and the etiological agent has been mainly ascribed to Spirometra erinaceieuropaei. However, recent studies have revealed that two other species, Spirometra mansoni and Spirometra asiana, coexist in Japan. Spirometra asiana is a new species recently discovered in Japan. Although morphological discrimination between these two species is difficult, molecular identification is useful. Therefore, to understand which species commonly parasitizes companion animals and wildlife in Japan, a preliminary study was performed based on mitochondrial DNA analysis. Eleven adult worms examined were identified as S. mansoni, suggesting that S. mansoni infects companion animals and wildlife commonly than S. asiana in Japan.

Molecular identification of sparganum of Spirometra mansoni isolated from the abdominal cavity of a domestic cat in Vietnam

Cats normally play a role of the definitive host in which the plerocercoid (sparganum), the second larval form of Spirometra spp., develops into an adult in the intestines. However, some cases of cats with visceral or subcutaneous sparganosis were sporadically reported worldwide. We herein documented the discovery of a sparganum in abdominal cavity of a domestic cat during a surgery of dystocia. The larva was molecularly identified as Spirometra mansoni, belonging to Type I, that was recently misidentified to be S. erinaceieuropaei in several Asian countries. This is the first report for sparganum of S. mansoni in the cat. The future study is necessary to provide further insights into the species of Spirometra causing sparganosis and spirometrosis in humans and other animals.

Molecular Characteristics of the Fatty-Acid-Binding Protein (FABP) Family in Spirometra mansoni-A Neglected Medical Tapeworm

The plerocercoid larva of the tapeworm Spirometra mansoni can parasitize humans and animals, causing serious parasitic zoonosis. The molecular characteristics and adaptive parasitism mechanism of Spirometra tapeworms are still unknown. In this study, 11 new members of the fatty-acid-binding protein (FABP) family were characterized in S. mansoni. A clustering analysis showed 11 SmFABPs arranged into two groups, and motif patterns within each group had similar organizations. RT-qPCR showed that SmFABPs were highly expressed in the adult stage, especially in gravid proglottid. A high genetic diversity of SmFABPs and relative conservation of FABPs in medical platyhelminthes were observed in the phylogenetic analysis. Immunolocalization revealed that natural SmFABP is mainly located in the tegument and parenchymal tissue of the plerocercoid and the uterus, genital pores, and cortex of adult worms. rSmFABP can build a more stable holo form when binding with palmitic acid to protect the hydrolytic sites of the protein. A fatty acid starvation induction test suggested that SmFABP might be involved in fatty acid absorption, transport, and metabolism in S. mansoni. The findings in this study will lay the foundation to better explore the underlying mechanisms of FABPs involved in Spirometra tapeworms as well as related taxa.

Integrated transcriptomic and proteomic analyses of plerocercoid and adult Spirometra mansoni reveal potential important pathways in the development of the medical tapeworm

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.

Spirometra mansoni sparganosis identified by metagenomic next-generation sequencing: a case report

A 30-year-old male patient had a cyst on the left hip and progressive enlargement for more than 2 months. Combined blood tests, magnetic resonance imaging, and pathology findings, cysticercosis infection was suspected. However, the treatment for cysticercosis was ineffective. We conducted a metagenomic next-generation sequencing (mNGS) analysis on the formalin-fixed, paraffin-embedded specimen of the patient's surgically excised tissue, and the results suggested Spirometra mansoni, mNGS was further confirmed by polymerase chain reaction and phylogenetic analysis of cytochrome c oxidase subunit 1 (cox1) gene. Based on these results, we found that mNGS provided a better method of diagnosing parasitic infections.

Identification of an enolase gene and its physiological role in Spirometra mansoni

Enolase is a crucial enzyme involved in the glycolytic pathway and gluconeogenesis in parasites. It also has been reported to function as a plasminogen receptor and may be involved in tissue invasion. In this study, the biochemical properties of the enolase of Spirometra mansoni (Smenolase) were investigated. The Smenolase gene was found to cluster closely with the enolase genes of Clonorchis sinensis and Echinococcus granulosus, and some functional motifs were identified as conserved. Smenolase was confirmed to be a component of the secretory/excretory products (ESPs) and a circulating antigen of spargana. Recombinant Smenolase expressed in vitro was able to bind to human plasminogen. Smenolase was detected in the eggs, testicles, and vitellaria of adult worms and the tegument of spargana. The transcription level of Smenolase was highest at the gravid proglottid stage. When spargana were cultured with glucose of different concentration in vitro, it was observed that the expression levels of Smenolase in the low-glucose groups were consistent with that of Smenolase in vivo. These results indicate that Smenolase is a critical enzyme involved in supplying energy to support the development and reproduction of the parasite, and it may also play a role in sparganum invasion.

A case of human breast sparganosis diagnosed as Spirometra Type I by molecular analysis in Japan

A 92-year-old Japanese woman presented with a mass in the left breast, and sparganosis was suspected by biopsy of the mass. The mass disappeared once, but it reappeared at the same site one year later. For a definitive diagnosis, the mass was surgically removed, and a sparganum-like worm was detected. The causative agent was confirmed as Spirometra Type I (most probably Spirometra mansoni) by mitochondrial DNA analysis. The serological examination also proved the case as sparganosis. Considering the presence of two Spirometra species (Type I and II) in Asia, particularly Japan, molecular analysis of the causative agents is highly recommended to understand the epidemiology, infection sources, and pathogenicity in humans in both species, if the parasite specimens are available.

Spirometra species from Asia: Genetic diversity and taxonomic challenges

Despite considerable controversy concerning the taxonomy of species within the genus Spirometra, human sparganosis and spirometrosis mainly in Asia and Europe has long been confidently ascribed to Spirometra erinaceieuropaei. Recently, the mitochondrial genomes of purported "S. erinaceieuropaei", "Spirometra decipiens" and "Spirometra ranarum" from Asia have been determined. However, it has been pointed out that the morphological criteria used for identifying these species are unsuitable and thus these identifications are questionable. In the present study, therefore, Spirometra samples from Asia were re-examined based on mitochondrial cytochrome c oxidase subunit 1 gene sequences and the identification of these species was discussed. Haplotype network and phylogenetic analyses revealed that: i) two distinct Spirometra species, Type I and Type II, are present in Asia and neither of which is close to likely European "S. erinaceieuropaei"; ii) Type I is genetically diverse and widely distributed, however Type II is known so far from Japan and Korea; iii) "S. decipiens" and "S. ranarum" reported from Asia are conspecific with Type I; iv) Type I is probably conspecific with Spirometra mansoni, and Type II may represent an undescribed species.

A case of mammary sparganosis due to infection with Spirometra mansoni

The authors report the case of a 56-year-old woman with mammary sparganosis due to infection with a plerocercoid tapeworm larva of Spirometra mansoni. Magnetic resonance imaging revealed an area of heterogeneous density in outer upper quadrant of the right breast, with a high likelihood of malignancy. During surgery for the removal of a granuloma, the parasite was discovered and excised. The authors review the pathological and imaging features of mammary sparganosis.

Subcutaneous sparganosis mimicking soft tissue tumor: a case report

Background

Sparganosis is a rare parasitic disease of humans caused by invasion of human tissue by plerocercoid tapeworm larvae (spargana) of the genus Spirometra species. This parasite commonly invades subcutaneous tissue but can appear in any tissue of the body.

Case presentation

Here, we report a case of a 33-year-old woman presented with a migrating painful swelling and erythema in right thigh for 6 months, which was initially misdiagnosed as soft tissue tumor. Magnetic resonance imaging revealed a multiple elongated tubular tracts in the medial aspect of right thigh, from which a long, wrinkled, whitish worm was surgically removed. The parasite was histopathologically identified as Spirometra mansoni.

Conclusion

Sparganosis is rare and physicians have little experience, so if suspected, should be included among the list of differential diagnosis and special serological test should be recommended before surgery.

Prevalence of Spirometra mansoni in dogs, cats, and frogs and its medical relevance in Guangzhou, China

BACKGROUND

Sparganosis is an important parasitic disease in Guangzhou and is mainly acquired through the consumption of frog meat or contact with fresh frogs infected by larval stages (spargana) of the tapeworm species Spirometra mansoni.

METHODS

In this study, the prevalence of intestinal S. mansoni infections (with adult parasites) in dogs and cats and of extraintestinal S. mansoni infections (with spargana) in frogs was assessed. In addition, a questionnaire survey was carried out among residents in Guangzhou City in order to evaluate their awareness about the medical and epidemiological relevance of Spirometra and sparganosis.

RESULTS

In total, the feces of 229 dogs and 116 cats were examined for eggs, and 1949 frogs were examined for spargana. Sixty-three dogs (27.5%) and 47 cats (40.5%) had eggs in their feces. Two hundred and sixteen out of 416 wild Rana tigrina rugulosa Wiegmann frogs examined were sparganum-positive, with an infection rate of 51.9%, while the infection rate in Rana limnocharis Boie was 35.1% (13/37). None of the tested farmed frogs (including R. tigrina rugulosa and Rana catesbeiana) was positive (0/1382). Analysis of the questionnaire revealed the following results: (1) about 41.0% of residents in Guangzhou had some knowledge of sparganosis or sparganum infection, and information in TV programs was the most important way that residents learned about sparganosis. (2) About 59.9% of the residents ate frog meat. Eating the meat, viscera, or blood of animals, e.g., frogs, snakes, pigs, chicken, mice, and birds, in an improper way might be the main means by which residents acquire the infection. (3) The risk of sparganum infection was higher in males than in females.

CONCLUSIONS

A high sparganum infection rate was observed in the wild frogs sold in agricultural product markets in Guangzhou. The infection was also serious in cats and dogs in Guangdong Province. With lifestyles and eating habits resulting in sparganum infection, it is necessary to focus on market management and community education in order to prevent the transmission of this disease in Guangzhou.

Bioinformatic analysis for structure and function of TCTP from Spirometra mansoni

OBJECTIVE

To predict structure and function of translationally controlled tumor protein (TCTP) from Spirometra mansoni by bioinformatics technology, and to provide a theoretical basis for further study.

METHODS

Open reading frame (ORF) of EST sequence from Spirometra mansoni was obtained by ORF finder and was translated into amino acid residue by DNAclub. The structure domain was analyzed by Blast. By the method of online analysis tools: Protparam, InterProScan, protscale, SignalP-3.0, PSORT II, BepiPred, TMHMM, VectorNTI Suite 9 packages and Phyre2, the structure and function of the protein were predicted and analyzed.

RESULTS

The results showed that the EST sequence was Sm TCTP with 173 amino acid residues, theoretical molecular weight was 19 872.0 Da. The protein has the closest evolutionary status with Clonorchis sinensis, Schistosoma mansoni, and Schistosoma japonicum. Then it had no signal peptide site and transmembrane domain. Secondary structure of TCTP contained two α -helices and eight β -strands.

CONCLUSIONS

Sm TCTP was a variety of biological functions of protein that may be used as a vaccine candidate molecule and drug target.

Immunoproteomic Analysis of the Excretory-Secretory Proteins from Spirometra mansoni Sparganum

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.

Electron microscopy of the separated outer tegument of the sparganum and its antigenicity

The author reported previously on separation of the outer tegument of the spargana (plerocercoids of Spirometra mansoni) using high concentration of urea solution. To determine which layer of the tegument is separated by this method, an electron microscopic analysis has been processed in this study. It was confirmed that the basement layer of the tegument is separated from the parenchyme of the sparganum. In addition, the antigenicity of the separated outer tegument against the human sparganosis patient sera was evaluated. Numerous antigenic proteins, including 16 and 55 kDa proteins, were noticed in the separated tegument; however, there were no diagnostic 31/36 kDa molecules in this tegument. The molecules reactive with the patient sera in the tegument are to be characterized in future studies.

Expression of TNF-α and IL-1β in splenic dendritic cells and their serum levels in mouse sparganosis

Sparganosis is a tissue invading helminthiasis infecting intermediate hosts, including humans. Strong immune responses are expected to occur in early phases of infection. Thus, we investigated cytokine expressions in splenic dendritic cells and in sera after experimental infection of mice. In splenic dendritic cells, TNF-α and IL-1β expression peaked at week 1 and week 3 post-infection (PI), respectively, and also early phase (week 2 PI) depressed cytokine expression was noticed. Serum IL-1β concentration increased significantly at week 2 PI and peaked at week 6 PI, and that of TNF-α peaked at week 6 PI. These results showed that pro-inflammatory cytokines, TNF-α and IL-1β, are chronologically regulated in mouse sparganosis.

Separation of the syncytial layer of spargana using urea

The tegument of tapeworms is known to be composed of an outer syncytial cytoplasm layer which includes microtriches and cytoplasmic organelles (= syncytial layer), and a parenchymatous cytoplasm layer that contains subtegumental cell nuclei (= subtegumental layer) and organelles. In the present study, separation of the syncytial layer of the sparganum, the plerocercoid stage of Spirometra mansoni, was tried using urea as the chemical reagent. Histological sections were prepared to visualize the status of separation after staining with hematoxylin and eosin. The results showed that the syncytial layer of the sparganum tegument which includes microtriches and cytoplasmic organelles were successfully separated from the parenchyma using 3 M urea.