• Parasites, Hosts and Diseases
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• v.34 no.1
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• pp.21-26
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• 1996

An experimental study was carried out to observe the effects of radiation on the infectivity of metacercariae of Gymnophalloines seoi to C3H mice. Oysters, the second intermediate host, were collected from an endemic area, and non-irradiated control, metacercaria-irradiation, and oyster-irradiation groups were prepared . One hundred metacercariae were infected orally to each mouse, and worm recovery rate was compared by groups at 7th day post-infection. In the metacercaria-irradiation group, the worm recovery rate was significantly reduced at radiation doses higher than 200 Gy, and the number of intrauterine eggs significantly reduced at doses over 50 Gy. In the oyster- irradiation group, 50 Gy significantly reduced both the worm recovery rate and number of uterine eggs. In the two groups, no worm was recovered at 1,000 Gy irradiation. Conclusively, irradiation of oysters with 200-1,000 Gy was effective to control infectivity of metacercariae to C3H mice, and could be adopted as a control measure for gymno-phalloidiasis.

• Parasites, Hosts and Diseases
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• v.38 no.2
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• pp.95-97
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• 2000

A 17 kDa protein from Clonorchis sinensis adults was purified by a procedure including Sephacryl S-200 HR gel filtration and Q-Sepharose anion exchange chromatography. The protein was proved to be a cysteine protease as it showed hydrolytic activity toward Cbz-Phe-Arg-AMC in the presence of dithiothreitol and was inhibited by specific inhibitors such as iodoacetic acid or trans epoxy-succinly-L-leucyl-amido(4 guanidino) butane. The polyclonal antibody raised against the protein reacted to 17 kDa proteins of trematodes such as Paragonimuf westermani, Fasciola hepatica, Opisthorchis viverrini, Gymnophalloides seoi, and Metagonimus yokogawai. The antibody recognized the 17 kDa and 16 kDa cysteine proteases purified from C. sinensis, P. westemani, and G. seoi as well. These results suggest that the 17 kDa protein may be a cysteine protease commonly present in trematodes.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.289-296
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• 1995

The surface ultrastructure of metacercariae and adults of Gymnophallokles seoi, the only known gymnophallid infecting humans, was observed by scanning electron microscopy. Metacercariae were ovoid or pyriform in shape and slightly concave ventrally. The oral sucker had two sizes of type I papillae, small and large, encircling its lip. Type I papillae were arranged in a row on both side oi the body. The ventral pit had several type I papillae on its inner surface. The ventral sucker was covered with cobble-stone like cytoplasmic processes and had 6 type I papillae on its lip. The surface of the body was covered with the tegumental spines except for the ventromedian area between the two suckers. The spines at anterior body were digitated into 3-5 points, and their size decreased at posterior one third or the body. Adult worms were rhomboid or ellipsoid in shape and covered with tegumental spines except for the ventromedian area. The shape and distribution of the tegumental spines and sensory papillae were similar to those of metacercariae. However, sensory papillae arranged in a row on the ventral surface of metacercariae were not observed in adults. The ventral pit became larger and more prominent as the fluke grew. It is suggested that the ventral pit function as an additional adhesive organ to the host tissue.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.207-213
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• 2012

The egg morphology of minute intestinal flukes (MIF) that can occur as human infections in the Republic of Korea, i.e., Metagonimus yokogawai, M. miyatai, M. takahashii, Heterophyes nocens, Heterophyopsis continua, Stellantchasmus falcatus, Stictodora fuscata, Pygidiopsis summa, and Gymnophalloides seoi, was studied in comparison with Clonorchis sinensis. The adult worms were obtained from residents of endemic areas, and their intrauterine eggs were studied and measured using light microscopy; the length, width, length-width ratio (LWR), and Faust-Meleney index (FMI). Several specimens were processed for scanning electron microscopy (SEM), and before gold-coating, the uterine portion of each fluke was etched with a sharp pin in order to expose the eggs. The MIF eggs were ovoid, pyriform, or elliptical with a size range of $21-35{\times}12-21{\mu}m$. S. fuscata eggs revealed the highest FMI (largest in the area) and lowest LWR, whereas P. summa eggs showed the lowest FMI and medium LWR. SEM revealed that G. seoi and S. fuscata had remarkably clean shell surface lacking the muskmelon-like structure which is prominent in C. sinensis eggs. In Metagonimus spp., H. continua, H. nocens, and S. falcatus eggs, minute surface ridges were recognizable though less prominent compared with C. sinensis. On the surface of P. summa eggs, thread-like curly structures were characteristically seen. The results revealed that important differential keys for MIF eggs include the length, width, area (FMI), shape of the eggs, and the extent of the muskmelon-like structure or ridges on their shell surface and operculum.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.345-387
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• 2023

Paleoparasitology is a discipline that applies existing conventional and molecular techniques to study parasites found in ancient ruins. This review focuses on the history of the discovery of parasites (mostly helminth eggs and larvae) in archaeological soil samples and mummies in Korea from the Three Kingdoms Period to the Joseon Dynasty (100 BCE-1910 CE). We also briefly review important milestones in global paleoparasitology. The helminth species reported so far in Korea included Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis (larva), Trichostrongylus sp. (larva), Paracapillaria philippinensis (syn. Capillaria philippinensis), Enterobius vermicularis, Fasciola hepatica, dicrocoeliids, Paragonimus westermani, Clonorchis sinensis, Metagonimus yokogawai, Pygidiopsis summa, Gymnophalloides seoi, Isthmiophora hortensis, Dibothriocephalus nihonkaiensis (syn. Diphyllobothrium nihonkaiense), and Taenia spp. tapeworms. The findings obtained by Korean paleoparasitologists/archaeologists have brought about deep insight into the status of helminthic infections in Korea's past populations. Continued paleoparasitological research is essential for further understanding of ancient parasites and parasitic diseases in Korea.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.399-408
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• 2017

A survey was performed to know the recent infection status of digenetic trematode metacercariae in clams and oysters from 4 sites in western coastal regions of the Republic of Korea (=Korea). Four species of clams (Mactra veneriformis, Ruditapes philippinarum, Cyclina sinensis, and Saxidomus purpuratus) were collected from Taean-gun, Chungcheongnam-do (Province), Buan-gun (County) and Gochang-gun, Jeollabuk-do, and oysters, Crassostrea gigas, from Shinan-gun, Jeollanam-do were transferred to our laboratory on ice and examined by the artificial digestion method. The metacercariae of Himasthla alincia were detected in 3 species of clams, M. veneriformis, R. philippinarum, and C. sinensis from the 3 surveyed areas. The positive rate and the mean density per clam infected were 98.9% (30.8 metacercariae) in M. veneriformis, 60.0% (5.0) in R. philippinarum, and 96.0% (28.4) in C. sinensis. The positive rate (mean density) of Acanthoparyphium tyosenense metacercariae in M. veneriformis was 50.0% (2.1) from Taean-gun and 70.0% (2.8) from Gochang-gun. The metacercariae of Parvatrema spp. were detected in M. veneriformis and R. philippinarum from Taean-gun and Gochang-gun; the positive rate (mean density) was 63.3% (4,123) and 50.0% (19) in M. veneriformis, and 6.7% (126) and 100% (238) in R. philippinarum from the 2 regions, respectively. The metacercariae of Gymnophalloides seoi were detected in all 30 oysters from Shinan-gun, and their average density per oyster was 646. From the above results, it has been confirmed that more than 3 species of metacercariae are prevalent in clams from the western coastal regions, and G. seoi metacercariae are still prevalent in oysters from Shinan-gun, Jeollanam-do, Korea.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.233-238
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• 1997

A small coastal village of Muan-gun, Chollanam-do, was surveyed for intesti- nal fluke infections, especially heterophyids such as Heterophwes nocens and Ftsiniopsis summc by fecal examination on 108 inhabitants. The egg Positive rate of heterophyids was very high. 75.0%, and that of other parasites was comparatively low.0.9-3.7% by parasite species . After treatment of 20 patients showing high E. P. G. with praziquantel and purging with Mgs04, total 3,864 specimens of H. nocens were collected from the diarrheic stools of all the patients treated (3-1,338 individuallyl and total 703 p. summc were harvested from 18 patients (1-170 individually), together loth several other species of flukes. Other flukes included Stictodora jlscotn (164 specimens from 4 patients), Heterophwopsis continuo (2 from 2 patients), and Gwmnophalloides seoi (4 from 3 patients). From this study, the sutra- veyed coastal area of Muan-gun, Chollanam-do was proven to be a new endemic focus of H. nocens and p. summa. The occurrence of a few infected cases surf:mists that this area should also be a low-grade endemic area of S. Juscctc, H. continuo, and G. seoi.

• Parasites, Hosts and Diseases
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• v.52 no.2
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• pp.201-204
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• 2014

This study was undertaken to characterize the properties of a 100 kDa somatic antigen from Metagonimus yokogawai. Monoclonal antibodies (mAbs) were produced against this 100 kDa antigen, and their immunoreactivity was assessed by western blot analysis with patients' sera. The mAbs against the 100 kDa antigen commonly reacted with various kinds of trematode antigens, including intestinal (Gymnophalloides seoi), lung (Paragonimus westermani), and liver flukes (Clonorchis sinensis and Fasciola hepatica). However, this mAb showed no cross-reactions with other helminth parasites, including nematodes and cestodes. To determine the topographic distribution of the 100 kDa antigen in worm sections, indirect immunoperoxidase staining was performed. A strong positive reaction was observed in the tegumental and subtegumental layers of adult M. yokogawai and C. sinensis. The results showed that the 100 kDa somatic protein of M. yokogawai is a common antigen which recognizes a target epitope present over the tegumental layer of different trematode species.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.155-162
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• 1998

Two endemic foci of heterophyid infections were discovered in coastal villages of Puan-gun. Chollabuk-do, and Sachon-gun. Kyongsangnam-do, Korea. Fecal examina- tions were performed on 153 inhabitants of Puan-gun and 138 of Sachon-gun, using cellophane thick smear and formalin-ether sedimentation technique. The helminth egg and/or protozoan cyst positive rate was 21.5% (33/153) in Puan-gun and 39.1% (54/138) in Sachon-gun. In Puan-fun, the egg Positive rate of heterophyids was the highest, 17.6%, and that of other parasites was 0.7-2.6% by parasite species. In Sachon-gun, that of heterophyids wa's 18.8%, followed by Clonorchis sinensis (12.3%). and other parasites (0.7-5.OBEI . Twenth-two (Puan-gun) and six (Sachon-gun) heterophyid egg Positive cases were treated loth praziquantel, and adult flukes were collected from their diarrheic stools. A total of 3,284 adult flukes of Heterophyes nocens was collected from all of the 22 patients treated in Puan-gun (3-778 individually) , and other trematodes were also collected from 2- 15 patients; Ftgidiopsis sumac, Stellcntchcsmus JcEcctus, Metogoninus Wokogaupci, M. miyntci, Stictodora Juscnta, Heterophwopsis continua, Acnnthopcrwphium kurognmo, and GWmnophaELoines seoi. In Sachon-gun, M. yokognwci (3,007 specimens), H. nocens (120), aud S. falcatus (46) were collected from 5 of 6 treated patients, and H. continuo and 5. tan each from one patient. The present study revealed that heterophyid flukes, especially If. nocens and M. Wokofowai, are prevalent in the southern and western coastal areas of Korea where fresh and/or brackish water fishes are popularly eaten raw.

• Parasites, Hosts and Diseases
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• v.45 no.1 s.141
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• pp.33-38
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• 2007

To know the prevalence of heterophyid trematodes among inhabitants of a southern coastal village, i.e., Sacho-ri, Gangjin-gun, Jeollanam-do(Province), 82 stool samples were examined on helminth eggs and protozoan cysts using Kato-Katz and formalin-ether sedimentation techniques. Total 33 people(40.2%) were positive for trematodes(Heterophyes nocens; 15 people, Pygidiopsis summa; 3, Metagonimus sp.; 4, Clonorchis sinensis; 7, Gymnophalloides seoi; 6) and/or protozoa(Entamoeba coli; 3). Among intestinal trematode egg positive cases, 17 were treated with praziquantel and their whole diarrheic stools were collected after purgation. Adult flukes of H. nocens(number of specimens=1,294), P. summa(386), Stellantchasmus falcatus(5), Stictodora lari(4), and Heterophyopsis continua(1) were collected using a stereomicroscope. To know the source of human H. nocens infections in this village, metacercarial infections in mullets(10) were examined and most H. nocens metacercariae(101/105, 96.2%) were found in the trunk portion. From above results, the surveyed coastal village has been newly known as an endemic focus of human H. nocens infection and consuming raw mullets was the presumable source of human heterophyid infections.