Taenia saginata Infection Misdiagnosed as Acute Cholecystitis in a Tibetan Patient,in China

The present study reports a rare case of Taenia saginata infection, which was initially diagnosed as acute cholecystitis in a Tibetan patient at the Qinghai-Tibetan Plateau pastoral area, China. A 45-year-old female was initially diagnosed with acute cholecystitis at a hospital in China. She had a slight fever, weight loss and constipation and complained of pain in the upper abdomen and left back areas. Increase of monocyte, eosinophil and basophil levels were shown. Taenia sp. eggs were detected in a fecal examination. An adult tapeworm approximately 146 cm in length, whitish-yellow color, was collected from the patient after treatment with traditional Chinese medicine. The adult tapeworm had a scolex and proglottids with genital pores. The scolex was rectangular shape with 4 suckers and rostellum without hooklet. The cox1 gene sequence shared 99.5–99.8% homology with that of T. saginata from other regions in China. The patient was diagnosed finally infected with T. saginata by morphological and molecular charateristics.     

Morphologic and Genetic Identification of Diphyllobothrium nihonkaiense in Korea

Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means ''long tapeworm of the East Sea'' for this newly analyzed diphyllobothriid tapeworm in Korea.     

First Clinical Cases of Spirometrosis in Two Cats in Korea

This study reports the first two clinical cases of spirometrosis caused by Spirometra sp. in cats in Korea. In these two cases, the cats vomited, and long proglottids of tapeworm were recovered. The sick cats presented with anorexia and lethargy. However, they unexpectedly showed no diarrhea, which is the main symptom of spirometrosis. Based on a fecal floatation test as well as morphological and molecular analyses, the parasite was diagnosed as Spirometra sp. The 2 cases were treated with praziquantel. This study suggests regular monitoring of health and deworming in companion animals, even when animals are well cared for, with regular preventive medication. Additionally, spirometrosis should be considered in the differential diagnosis in cases of gastrointestinal symptoms in Spirometra endemic areas.     

Infection of Taenia asiatica in a Bai Person in Dali,China

We report here a human case of Taenia asiatica infection which was confirmed by genetic analyses in Dali, China. A patient was found to have symptoms of taeniasis with discharge of tapeworm proglottids. By sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, we observed nucleotide sequence identity of 99% with T. asiatica and 96% with T. saginata. Using the cytochrome b (cytb) gene, 99% identity with T. asiatica and 96% identity with T. saginata were found. Our findings suggest that taeniasis of people in Dali, China may be mainly caused by T. asiatica.     

Chinchilla laniger can be used as an experimental model for Taenia solium taeniasis

Chinchilla laniger has been reported as an experimental definitive host for Taenia solium; however no information about its suitability and yield of gravid tapeworm proglottids containing viable and infective eggs has been published. In total 55 outbred female chinchillas were infected with 4 cysticerci each; hosts were immunodeppressed with 6 or 8 mg of methyl-prednisolone acetate every 14 days starting the day of infection and their discomfort was followed. Kinetics of coproantigen ELISA or expelled proglottids was used to define the infection status. Efficiency of tapeworm establishment was 21% and of parasite gravidity was 8%; chinchillas showed some degree of suffering along the infection. Viability of eggs obtained from gravid proglottids was tested comparing methods previously published, our results showed 62% viability with propidium iodide, 54% with trypan blue, 34% with neutral red, 30% by oncosphere activation and 7% with bromide 3-(4,5-dimetil-tiazol-2-il)-2,5-difenil-tetrazolio (MTT) reduction; no statistical differences were obtained between most techniques, except activation. Four piglets were infected with 50,000 eggs each, necropsy was performed 3 months later and, after counting the number of cysticerci recovered, the percentage of infection was similar to data obtained with T. solium eggs recovered from humans. Our results demonstrate that the experimental model of T. solium taeniasis in C. laniger is a good alternative for providing eggs and adult tapeworms to be used in different types of experiments; optimization of the model probably depends on the use of inbred hosts and on the reduction of infected animals' suffering.     

A Case of Diphyllobothrium nihonkaiense Infection as Confirmed by Mitochondrial COX1 Gene Sequence Analysis

Diphyllobothrium nihonkaiense has been reported in Korea as Diphyllobothrium latum because of their close morphologic resemblance. We have identified a human case of D. nihonkaiense infection using the mitochondrial cytochrome c oxidase subunit I (cox1) gene sequence analysis. On 18 February 2012, a patient who had consumed raw fish a month earlier visited our outpatient clinic with a long tapeworm parasite excreted in the feces. The body of the segmented worm was 2 m long and divided into the scolex (head) and proglottids. It was morphologically close to D. nihonkaiense and D. latum. The cox1 gene analysis showed 99.4% (340/342 bp) homology with D. nihonkaiense but only 91.8% (314/342 bp) homology with D. latum. The present study suggested that the Diphyllobothrium spp. infection in Korea should be analyzed with specific DNA sequence for an accurate species identification.     

Polyacrylamide gel electrophoresis in the differentiation of Taenia (cestoda) by total protein

Bursey C. C., Mckenzie J. A. & Burt M. D. B. 1980. Polyacrylamide gel electrophoresis in the differentiation of Taenia (Cestoda) by total protein. International Journal for Parasitology10: 167–174, Step-gradient polyacrylamide gels were used to examine total protein in 3 taeniid species. Preliminary investigations revealed that band patterns of different parts of the taeniid strobila were basically identical; hence, individual worms were useful for analysis regardless of their state of development when collected. Using Hymenolepis diminula as a control, the band pattern for each of Taenia taeniaeformis, T. macrocystis and T. pisiformis was found to be species specific with marked differences. The procedure was adapted for use under the more adverse conditions present in field laboratories. Small quantities of tapeworm material used in analysis also allows specific differentiation of single proglottids of Taenia spontaneously expelled from live hosts.     

Adaptation of Haplobothrium globuliforme (Cestoda: Pseudophyllidea) to the intestinal architecture of the bowfin (Amia calva L)

Haplobothrium globuliforme maintains its position in the proximal mid-gut epithelium of Amia calva with the aid of tentacles, i.e., proboscides, everted from scolices of a primary strobila and craspedote proglottids of a secondary strobila. Weakly developed scolices of the secondary strobila appear to have little holdfast action, but the distinctly craspedote proglottids of these individuals project into the intestinal mucosa, altering the configuration of gut epithelial cells and pushing the tapeworm deeper into mucosal crypts. The basement membrane underlying the epithelium appears to act as a barrier that prevents tapeworms from penetrating into the deeper tissue layers of the lamina propria, muscularis mucosa, or submucosa. Scolex tegument modification occurs at the point of contact with host basement membrane. A mild background infiltrate of lymphocytes and granulocytes was evident adjacent to the scolex and proglottid tegument. There was no evidence of blood vessel proliferation, edema, mast cell degranulation, eosinophilia, or subsequent collagen formation associated with tapeworm activity.     

Occurrence of a Hybrid Between Taenia saginata and Taenia asiatica Tapeworms in Cambodia

Human infection with Taenia asiatica or a hybrid between Taenia saginata and T. asiatica has not been reported in Cambodia. We detected for the first time a hybrid form between T. saginata and T. asiatica in Preah Vihear Province, Cambodia. An adult tapeworm specimen, i.e., 75 cm long strobila without scolex, was expelled from a 27-year-old man after praziquantel medication and purging. It was morphologically indistinguishable between T. saginata and T. asiatica. Several proglottids were molecularly analyzed to confirm the tapeworm species. The mitochondrial gene encoding cytochrome c oxidase subunit 1 (cox1) and nuclear genes encoding elongation factor-1α (ef1) and ezrin-radixin-moesin (ERM)-like protein (elp) were sequenced, and a single-allele analysis was performed to confirm the haploid genotype. The results revealed that our sample showed a discrepancy between the mitochondrial and 2 nuclear genes. It possessed homozygous sequences typical of T. saginata at cox1 and ef1 loci. However, it was heterozygous at the elp locus, with 1 allele in T. asiatica (elpA) and 1 in T. saginata (elpC), which indicates that it is a hybrid between T. saginata and T. asiatica. The present results confirmed the presence of a hybrid between T. saginata and T. asiatica in Cambodia and strongly suggest the existence of also ‘pure’ T. asiatica in Cambodia.     

Echinococcus granulosus: ovicidal activity of praziquantel and bunamidine hydrochloride

Eggs of Echinococcus granulosus either released from or contained within the proglottids were treated with praziquantel and bunamidine hydrochloride at 37 C for 1 hr and then administered orally to mice and gerbils to test their infectivity. Praziquantel did not possess absolute ovicidal activity against E. granulosus eggs either within or outside the proglottids and bunamidine hydrochloride did not kill them within the proglottids. These findings bear on the use of praziquantel in control programs.     

Diplogonoporiasis in Japan: genetic analyses of five clinical isolates

Infection of the whale tapeworm Diplogonoporus balaenopterae (Diphyllobothriidae) is occasionally found in humans, especially among Japanese. In the present study, we analysed the nucleotide sequences of the 18S rDNA, ITS1 and cox1 genes of the immature and mature proglottids of Diplogonoporus species recovered from five Japanese patients. The nucleotide sequences of 18S rDNA, ITS1 and cox1 showed little, if any, intraspecific divergence. Phylogenetic analyses of several diphyllobothriid species revealed a close relationship of Diplogonoporus isolates with the cetacean tapeworm Diphyllobothrium stemmacephalum. The results suggest that the genus Diphyllobothrium is paraphyletic and raise a question regarding the validity of the genus Diplogonoporus.     

Morphological differences and molecular phylogenetic relationship of two tapeworm species,Moniezia expansa and Moniezia benedeni,collected from domestic ruminants in northern Vietnam

Moniezia expansa and M. benedeni are two common tapeworm species of domestic ruminants over the world. However, their morphological and molecular data are available for limited specimens from a few countries. In the present study, we compared morphological characteristics of these two species collected from goats and cattle in northern Vietnam and analyzed their phylogenetic relationship based on the 5.8S and second internal transcribed spacer (ITS2) of nuclear ribosomal DNA and the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species are clearly distinguishable from one another not only in the morphological appearance of the interproglottidal glands but also in the gross appearance of mature and gravid proglottids. Molecular analyses revealed that the 5.8S-ITS2 sequences of Vietnamese M. expansa were highly similar (99.7%) to the sequences from Japan and India, and made a common clade, which was clearly distinct from M. benedeni of Vietnam. For cox1 sequences, Vietnamese M. expansa showed a high similarity to and were grouped with the sequences from Ethiopia and some sequences from Senegal and China to make a common clade, which was separated from the remaining clades of Senegal and China. The cox1 sequences of M. benedeni from China, Vietnam, and Senegal were far distant (10.0–15.9%) from each other. The results of this study suggest that more sequence data of Moniezia species with details of morphological features from various geographical locations should be obtained to clarify the taxonomic status of Moniezia species.     

Intestinal immunity suppresses carrying capacity of rats for the model tapeworm, Hymenolepis diminuta

Hymenolepis diminuta is a parasitic tapeworm of the rat small intestine and is recognized as a useful model for the analysis of cestode-host interactions. In this study, we analyzed factors affecting the biomass of the tapeworm through use of rat strains carrying genetic mutations, namely X-linked severe combined immunodeficiency (xscid; T, B and NK cells deficiency), nude (rnu; T cell deficiency), and mast cell deficient rats. The worm biomass of F344-xscid rats after infection with 5 cysticercoids was much larger than control F344 rats from 3 to 8?weeks. The biomass of F344-rnu rats was also larger than the controls, but was intermediate between F344-xscid and control rats. These observations demonstrated that host immunity can control the maximal tapeworm biomass, i.e., carrying capacity, of the rat small intestine. Both T cell and other immune cells (B and NK cells) have roles in determining the carrying capacity of tapeworms. Total worm biomass and worm numbers in mast cell deficient rats (WsRC-Ws/Ws) were not significantly different from control WsRC-+/+ rats after 3 and 6?weeks of primary infection. Mast cell deficient rats displayed reinfection resistance for worm biomass but not worm expulsion. These findings suggest that the mast cell has a role for controlling the biomass of this tapeworm in reinfection alone, but does not affect the rate of worm expulsion. Overall, our findings indicate that the mast cell is not a major effector cell for the control of the carrying capacity of tapeworms. The identity of the major effector cell remains unknown.     

An Oxidation Reduction Method for Stain Differentiation

The difficulty in differentiating carmine-stained tapeworm proglottids is well known to those who have undertaken the task. Ordinary methods of differentiation, with 0.5% or 1% HCl, leave considerable amounts of color on the external tissues, a fact which not only is objectionable, but also renders it difficult to discern the morphology of internal organs clearly. We have found a method by which the external tissues are rendered colorless, yet the internal orgians remain well stained.     

A new triaenophorid tapeworm from blackfish Centrolophus niger

Milanella familiaris n. gen. and n. sp. (Bothriocephalidea: Triaenophoridae) is proposed to accommodate a new cestode from blackfish Centrolophus niger (Gmelin) (Perciformes: Centrolophidae). Milanella is characterized as follows: trapeziform, i.e., markedly craspedote proglottids with a velum-like posterior margin and horn like lateral projections; pyriform uterine sac in the first gravid proglottids; arrow-shaped scolex with well-developed apical disc and prominent posterior margins; strobila with intensively stained corpuscles, most numerous in the anterior part; deeply lobated ovary; absence of a neck; a large, pyriform, thin-walled cirrus-sac with the proximal part bent anteromedially; vagina posterior to the cirrus-sac; and cortical vitelline follicles. Milanella most closely resembles Bathycestus Kuchta and Scholz, 2004, Pistana Campbell and Gartner, 1982, and Probothriocephalus Campbell, 1979, differing mainly in the shape of proglottids and uterine sac.     

Thymidylate synthase activity in the development of Hymenolepis diminuta

Extracts of the tapeworm, Hymenolepis diminuta, catalyse N5,10-methylene-tetrahydrofolate-dependent release of tritium from [5-3H]dUMP, indicating the presence of thymidylate synthase. The enzyme activity was found in immature, mature and gravid proglottids, as well as in immature and mature oncospheres. The reaction showed pH optimum at 7.5. Its Michaelis constants were approximately 2 and 15 microM for dUMP and (+/-), L-N5,10-methylenetetrahydrofolate, respectively. Incubation of the tapeworm extracts with 5-F-[3H]dUMP and N5,10-methylenetetrahydrofolate resulted in formation of a labelled complex, separable under conditions of SDS polyacrylamide electrophoresis (mol. wt. of approx. 34,000), corresponding to thymidylate synthase subunit. Results of gel filtration of the above complex, under nondenaturing conditions, pointed to a dimeric structure of the enzyme.