• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.233-237
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• 2006

We postulated that apolysis was processed in accordance with apoptotic changes occurring in a cestode, Spirometra erinacei (Pseudophyllidea). We cloned the novel putative apoptosis-associated gene from S. erinacei via screening of a S. erinacei cDNA library with a ced-3 gene (activator of apoptosis) probe from Caenorhabditis elegans. We identified a 261-bp cDNA sequence, which encodes for an 86-amino acid protein. The cloned gene expression was observed in the neck and gravid proglottids via Northern blotting, using cloned cDNA inserts as probes, but the clone was not expressed in any of other tissues. We suggest that this gene may be involved in the apolysis of S. erinacei during normal tissue development and differentiation in cestode parasites.

• Molecules and Cells
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• v.23 no.3
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• pp.379-390
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• 2007

We sequenced and characterized the complete mitochondrial genome of the Japanese fish tapeworm D. nihonkaiense. The genome is a circular-DNA molecule of 13607 bp (one nucleotide shorter than that of D. latum mtDNA) containing 12 protein-coding genes (lacking atp8), 22 tRNA genes and two rRNA genes. Gene order and genome content are identical to those of the other cestodes reported thus far, including its congener D. latum. The only exception is Hymenolepis diminuta in which the positions of trnS2 and trnL1 are switched. We tested a PCR-based molecular assay designed to rapidly and accurately differentiate between D. nihonkaiense and D. latum using species-specific primers based on a comparison of their mtDNA sequences. We found the PCR-based system to be very reliable and specific, and suggest that PCR-based identification methods using mtDNA sequences could contribute to the study of the epidemiology and larval ecology of Diphyllobothrium species.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.503-507
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• 2016

The genus Spirometra belongs to the family Diphyllobothriidae and order Pseudophyllidea, and includes intestinal parasites of cats and dogs. In this study, a plerocercoid labeled as Spirometra mansonoides from the USA was examined for species identification and phylogenetic analysis using 2 complete mitochondrial genes, cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit 3 (nad3). The cox1 sequences (1,566 bp) of the plerocercoid specimen (USA) showed 99.2% similarity to the reference sequences of the plerocercoid of Korean Spirometra decipiens (GenBank no. KJ599679), and 99.1% similarity in regard to nad3 (346 bp). Phylogenetic tree topologies generated using 4 analytical methods were identical and showed high confidence levels with bootstrap values of 1.00, 100%, 100%, and 100% for Bayesian inference (BI), maximum-likelihood (ML), neighbor-joining (NJ), and maximum parsimony (MP) methods, respectively. Representatives of Diphyllobothrium and Spirometra species formed a monophyletic group, and the sister-genera status between these species was well supported. Trapezoic proglottids in the posterior 1/5 region of an adult worm obtained from an experimentally infected cat were morphologically examined. The outer uterine loop of the uterus coiling characteristically consisted of 2 complete turns. The results clearly indicated that the examined Spirometra specimen from the USA matched to S. decipiens very well, and indicated possible presence of the life cycle of this species in this region.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.155-168
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• 1986

In Korea, lots of Israeli carp (Cyprinus carpio) are cultured by means of net cages in dams and lakes, but many carp have been subjected to heavy infestation of the cestoid, Bothriocephalus opsariichthydis. Nevertheless the parasitic state and life history of the cestoid are not yet reported. This reason led the author to study the parasitic state and life history of B. opsariichthydis parasitized in the carp in order to take effective control measures against its damage. Israeli carp were sampled from two fish farms, in Taech'on and Kyongch'on. After dissection of the specimens, the cestoid were obtained and the parasitic rates were examined. After taking the eggs from adult worms, the development of the eggs were observed. Coracidia were exposed to four kinds of crustaceans in order to investigate the infection rate and development of the larva. Finally, tile development of the larva in the final host was investigated. The fully mature eggs were in the cleavage stage, when they are released, and the size ranged 47.5 to 55.0 $(50.9){\times}30.0$ to 32.5 (31.1) um, in the state of under-developed coracidia and blastomeres. The parasitic rate of the cestoid in Israeli carp from Taechon was $55.5\%$ in 1984 and $21.6\%$ in 1985, that from Kyongchon was $64.7\%$ in 1984, and color carp from Kusan was $14.9\%$ in 1984. The eggs were hatched to coracidia within 48 hours under 26 to $28^{\circ}C$. The cestoid showed a strong affinity to Thermocyclops hyalinus and Paracyclops fimbriatus and the infection rates were $93.5\%$ and $75.5\%$, respectively. At 14 days after the infection to Thermocyclops hyalinus and Paracyclops fimbriatus, the larvae of the cestoid grew into fully developed procercoids; 207 to $226 (214){\times}90$ to 102 (94) um in size. Sixty days after carp have ingested the Thermocyclops hyalinus infected with the fully developed procercoids, the larvae of the cestoid matured into adult worms in the intestines of the carp.