• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.129-140
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• 1987

The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate tost of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were encysted and examined with light. scanning and transmission electron microscopes for morphological features. On the surface of iBetacercariae, three types of sensory FaFillae were identified. Large domed papillae ($3~5{\mu\textrm{m}}$), which were covered with wrinkled plasma n!embrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12~13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae ($2~3{\mu\textrm{m}}$), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30~32 pairs) and dorsal surfaces (40~42 Pairs). Ciliated Papillae ($0.8~1.5{\mu\textrm{m}}$) were observed about 5~6 in number around the oral sucker and 3~5 pairs each on the ventral and dorsal surface of the body. Single Fcinted spines covered the entire surface of the body except around the excretory pore. Spines on the anterior fart of the body were 0.9~2.0${\mu\textrm{m}}$ in length and $45~55/100{\mu\textrm{m}}$2 in number, and were gradually reduced in length ($0.4~1.4{\mu\textrm{m}}$) and in nuns.her ($12~27/100{\mu\textrm{m}}$2) toward the posterior part. The body wall of p. westermoni metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave ($0.15~0.55{\mu\textrm{m}}$) and spherical ($0.08~0.16{\mu\textrm{m}}$) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and rihoEorses, T-ere observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.291-299
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• 1987

The cattle liver flukes were collected at daughter house and classified with gross morphology. The hepatica type was only 14 flukes (4.7%) and the gigantica type was 284 flukes (95.3%) among total 298 flukes collected. In order to determinate the intermediate host of the flukes, artificial infection with the miracidia to snail hosts, Radix auricularia and Austropelea ollula, were successfully carried out, but the development in the later was terminated at the sporocyst stage. Intermediate host of the cattle flukes used to hibernate in deep part of the stubbles of rice pady. The number of A. ollula that has been collected from a rice stubble was ranged 0 to 19. Their mean number was 7 snails per the stubble. In artificial infection with miracidia, the reasonable number of them were 1 to 9 and the snail size was 2 to 5mm in length. The productivility of metacercaria in the intermediate host was observed. The metacercarial production per snail was ranged 5.5 to 48.0 per one miracidium.

• YAKHAK HOEJI
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• v.29 no.1
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• pp.32-38
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• 1985

The anthelmintic substance of the roasted fruits of Prunas mume against Clonorchis sinensis was isolated and its structure was identified by chemical and physical methods. The results obtained from the experiments are as follows: 1) The methanol extract of the roasted fruits of P. mume was fractionated into four parts: petroleum ether, ethyl ether, ethyl acetate and water soluble part. Among these, etherial fraction was found to have strong wormicidal effect on liberated metacercaria of Clonorchis sinensis. 2) From the etherial fraction, the wormicidal substance was isolated by silica gel, polyamide and sephadex column chromatography and identified to be 5-hydroxymethylfurfural (5-HMF) by chemical and spectral data. 3) 5-HMF was synthesized and administered to the rabbits infected with C. sinensis. On the 2nd day after administration, the EPG (eggs per gram in feces) reached to the maximal value. Among the adult worms isolated from the bile duct of the treated animal, 84% of worms were damaged morphologically. 4) The content of 5-HMF in the fruits of P. mume which were roasted in an oven at $90-110^{\circ}C$ for 52 hours and that in the fresh fruits was evaluated by HPLC. The content of 5-HMF was 0.8% in the roasted fruits and 0.02% in the fresh ones.

• Research in Community and Public Health Nursing
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• v.21 no.2
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• pp.242-251
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• 2010

Purpose: This study investigated the factors of C. sinensis infection among the residents in vicinity of the Nakdong River and the infection status of fishes in the stream with C. sinensis maetacercaria. Methods: Selected five regions of the Nakdong River and collected freshwater fishes from the stream to examine their metacercarial infections; and studied the status and causes of C. sinensis infection in 552 residents living within 5 kilometers from the river. Results: Among the 552 residents studied, 13.8% were infected with C. sinensis, and among 379 freshwater fishes of 20 species collected from the five regions, 41 fishes of 8 species were infected with C. sinensis metacercaria. Conclusion: In order to prevent human C. sinensis infection and transition to chronic liver ions, we need to develop and apply good programs such as continuous health education, personal hygiene improvement, active medical treatment for those infected with C. sinensis, and residents’ voluntarily stop of eating freshwater fishes in the raw state.

• Parasites, Hosts and Diseases
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• v.43 no.4 s.136
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• pp.161-164
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• 2005

A survey was performed in order to determine the infection status of the metacercariae of heterophyid fluke in two goby species, Boleophthalmus pectinirostris and Scartelaos sp., collected from Gangjin-gun, and Shinan­gun, Sooncheon-shi, Jeollanam-do, Republic of Korea. A total of three metacercariae of Heterophyopsis continua was found in only one B. pectinirostris $(10.0\%)$ from Gangjin-gun. Heterophyes nocens metacercariae were detected in 24 B. pectinirostris $(96.0\%)$ and 14 Scartelaos sp. $(63.6\%)$ from Shinan-gun. Heterophyopsis continua metacercariae were found in 11 B. pectinirostris $(44.0\%)$ and 21 Scartelaos sp. $(95.5\%)$ from Shinan-gun. Stictodora fuscata metacercariae were detected in 18 B. pectinirostris $(72.0\%)$ from Shinan-gun. No metacercariae were detected in 20 B. pectinirostris from Sooncheon-shi. From the above results, this study is the first to prove that B. pectinirostris and Scartelaos sp. serve as the second intermediate hosts of some heterophyid flukes in Korea.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.101-104
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• 2008

Metacercariae of Acanthoparyphium marilae Yamaguti, 1934 (Digenea: Echinostomatidae) were discovered in an intertidal clam, Mactra veneriformis, in a southwestern coastal area of the Republic of Korea. A total of 128 metacercariae were detected from 10 clams examined. They were round, 320 m in average diameter, with 23 collar spines. They were fed experimentally to chicks, and 10 days later adult flukes were obtained. The adults were morphologically characterized by the head collar with a single row of 23 dorsally uninterrupted spines, without special end group spines, a round ventral sucker, 2 round and tandem testes, and vitellaria extending at lateral fields from the posterior extremity not beyond the middle level of the posterior testis. The most characteristic feature of this species was the limited distribution of vitellaria, which differs from Acanthoparyphium tyosenense Yamaguti, 1939, the metacercariae of which are encysted in the same mollusk species. This is the first report in which the metacercariae of this species were detected, and the intertidal bivalve, M. veneriformis, has been identified as a second intermediate host for A. marilae.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.109-112
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• 2008

A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.199-204
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• 2007

Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical ($391.1{\times}362.5{\mu}m$), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.229-232
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• 2007

The WD40-repeat proteins serve as a platform coordinating partner proteins and are involved in a range of regulatory cellular functions. A WD40-repeat protein (CsWD1) of Clonorchis sinensis previously cloned is expressed stage-specifically in the tegumental syncytium of C. sinensis metacercariae. In the present study, interact-ing proteins with the CsWD1 protein was purified by immunoprecipitation and 2 dimension gel electrophoresis from the C. sinensis metacercaria soluble extract, and tryptic peptides were analyzed by LC/ESI-MS. Putative partner proteins were annotated to be actin-2, glyceraldehyde-3-phosphate dehydrogenase, and hypothetical and unmanned proteins. The CsWD1 protein was predicted to contain 3 conserved actin-interacting residues on its functional surface. With these results, the CsWD1 protein is suggested to be an actin-interacting protein of C. sinensis.

• Parasites, Hosts and Diseases
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• v.39 no.4
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• pp.329-332
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• 2001

More than 1,500 clams of Corbicula fluminea, the most favorable food source of freshwater bivalves in Korea, were collected from 5 localities to examine cercarial and metacercarial infection with Echinostoma cinetorchis. Although 3 clams infected with suspicious E. cinetorchis metacercariae out of 200 specimens collected at Kangjin, Chollanam-do were detected, no cercarial and metacercarial infections with E. cinetorchis were observed in field-collected Corbicula specimens. In the susceptibility experiments with laboratory-reared clams, those infected with miracidia of E. cinetorchis did not release their cercariae up to 60 days after infection. To confirm the identity of second intermediate host of E. cinetorchis experimentally, a total of 30 clams were exposed to the cercariae from Segmentina hemisphaerula that had been infected with miracidia of E. cinetorchis. The clams were susceptible to cercariae of E. cinetorchis with an infection rate of 93.3%. Metacercariae from clams taken more than 7 days after cercarial exposure were fed to rats (S/D strain), and adult worms of E. cinetorchis, characterized by 37-38 collar spines on the head crown, were recovered from the ileocecal regions. This is the first report of C. fluminea as a possible second intermediate host of E. cinetorchis.