• Parasites, Hosts and Diseases
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• 제37권2호
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• pp.65-70
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• 1999

Plagiorchis muris has been found in both been found in both house and field rats as well as in humans. The infection status of th second intermediate hosts of P.muris is prerequisite in understanding their biological features in an ecosystem. Six species of dragonflies were caught in a wide range of areas in Korea;and they were Sympertrum darwinianum, S.eroticum, S. pedomontanum, S. infuscatum, Pantala flavoscens, Caloteryx atrata, and Othertrum albistylum speciosum. The occurrence of P. muris metacercariae in dragonflies was nationwide with various infection rates. The metacercarial burden of P. muris in the surveyed areas was the highest in S. eroticum followed by S. darwinianum, S. pedomontanum, and C. atrata. The highest infection rate by P. muris metacercariae was found in S. darwinianum followed by S. eroticum. The metacercarial buredn was particularly heavy in the dragonflies found in Hamyang-gun and Kosong-gun, Kyongsangnam-do. It is, therefore, likely that dragonflies play a significant role as the second intermediate hose in the life cycle of P. muris in Korea.

• 대한수의학회지
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• 제9권2호
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• pp.7-18
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• 1969

Researches to determine the infectious status on the pancreatic fluke, Eurytrema pancreaticum(Janson 1889) Looss, 1907, were made into several slaughter hauses at four different districts through seven years from 1963 to 1969. The infection rate showed 2962 positive of 5974 heads (49.6%) of cattle at the Seoul first slaughter hause in Seoul, 881 positive of 1021 heads (86.3%) in Cheju, and six(6) positive of 56 heads (11.1%) at Suwon, 58 positive of 306 heads(19.0%)at Joenju. The infection rate 53.1%, (2907 positive heads of total 7357 heads exammed) is the representative infection rate at the cattle eurytremiasis in Korea. It showed little variation through a year and was increased as compared with those of the past period, from 1915 to 1945. Fecal examinations in order to find out the local distribution of the pancreatic fluke were conducted on cattle, sheep, and goats raised in four districts, showing two(2) of 269 heads (0.7%) in Kyonggi-do, 41 of 212 heads (19.3%) in Cheju-do, and negative in both Chungnam-do and Joenbuk-do. When an artificial infection wss performed on rabbits and goats with metacercaria of the pancreatic fluke, Parenchyma of their pancreas were degenerated and the ducts were dilated. When cattle and sheep were infected naturally, the pancreatic ducts were also dilated, the wall was thickened, and adenomatous and epithelial hyperplasia was appeared. The conclusion, putting the foregoing pathological changes, has been arrived at chronic hyperplastic pancreatitis in the eurytremiasis of cattle, sheep, goats and rabbits.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.627-639
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• 2015

Metagonimus yokogawai (Katsurada, 1912) Katsurada, 1912 (Trematoda: Heterophyidae) is parasitic in the small intestine of mammals including man and birds in Far Eastern Russia, Korea, Japan, China, and Taiwan. In the present study, the metacercariae and adults of M. yokogawai were redescribed to designate a neotype of this fluke together with reviews of previous studies including study histories from the first discovery to now. We particularly, attempted to review the study histories and morphological descriptions of M. yokogawai for the species validity, and compared with the morphological characteristics and life cycles of the closely related species, Metagonimus takahashii and Metagonimus miyatai. Finally, we proposed a differential key for the 8 known Metagonimus species distributed in East Asia. Metacercariae were obtained from the body muscles of sweetfish (Plecoglossus altivelis) collected in the Asahi River at Takebe-cho, Kita-ku, Okayama City, Okayama Prefecture, Japan. Adults were recovered from the small intestine of Syrian golden hamsters, to which the metacercariae had been fed 14 days before. A neotype was selected out of the present adult specimens. The Asahi River at Takebo-cho became the type locality of M. yokogawai. In conclusion, the present review shows that M. yokogawai, M. takahashii, and M. miyatai are valid and discriminated by means of morphological characteristics.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.165-169
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• 2008

Microphallus species occur primarily as intestinal parasites of birds and mammals, and metacercariae of a new species belonging to this genus have been discovered from the crab, Macrophthalmus dilatatus, in the Republic of Korea. The metacercaria of this fluke was round with 2 thick walls, and the excysted one had mature genital organs. The adult flukes recovered from experimentally infected chicks had numerous intrauterine eggs, well-developed pars prostatica, widely bifurcating ceca, and prominent uterine bulge. After observing internal structures, it was concluded that this species is different from any other known Microphallus spp. Based on the morphology of metacercariae and adult flukes, we describe this specimen as a new species, Microphallus koreana n. sp.

• Parasites, Hosts and Diseases
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• 제28권1호
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• pp.39-44
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• 1990

실험실 내에서 또아리물달팽이(Hippeutis cantori)를 중간숙주로 한 이전고환극구흡충(E. cinetorchis)의 생활사를 관찰하였다. 실험감염시킨 흰쥐로부터 회수한 충체에서 충란을 얻어 28$^{\circ}C$의 물에서 배양하였던 바, 배양 24일에 탈각 부화하였으며 부화한 미라시디움(miraciaium)은 체표면에 밀생해 있는 섬모를 이용하여 매우 빠른 속도로 유영하였고, 크기는 평균 $102.5{\times}36.8{\mu\textrm{m}}$이었다. 미라시디움을 실험실에서 부화시킨 패류에 접촉 감염시 킨 후 유미유충의 유출_여부와 파쇄법에 의한 유충의 감염 상태를 조사하였다. 피낭유충은 검사한 16마리 패류 모두에서 17~321개가 검출되었고, 레디아(regia)와 유미유충(cercaria)이 3마리의 패류에서 다수가 발견되었다. 레디아는 길쭉한 자루 모양이었으며 평균 $1.43{\times}0.24{\;}mm$의 크기이었고, 근육성의 인두와 길쭉한 맹장 및 성숙한 유미유충을 보유하고 있었다. 유미유충은 타원형의 몸체와 막대 모양의 꼬리로 이루어져 있었고 몸체에는 두개 의 흡반과 인두 및 특징적인 광택성의 배설 과립이 존재하였다. 피낭유충은 원형 또는 타원형이었으며 평균 $139.0{\times}134.4{\mu\textrm{m}}$이었다. 감염 후 17일에 회수한 충체는 크기가 평균 $10.3{\times}2.4{\;}mm$이었으며, 두극의 수 및 배열, 고환의 수 및 위치 등에 있어서 이전고환극구흡충의 특징적인 소견을 나타내었다. 자연 유출된 유미유충은 전혀 관 찰할 수 없었다. 이 연구를 통하여 우리 나라에서 논과 수로에 흔히 서식하는 또아리물달팽이가 이전고환극구흡충의 제 1중간 숙주이고 동시에 제 2중간숙주가 될 수 있음을 실험적으로 확인하였다. 이러한 중간숙주로서의 역할은 자연계에서도 이루어질 것으로 추측된다.

• Parasites, Hosts and Diseases
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• 제38권1호
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• pp.9-15
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• 2000

A scanning electron microscopic study was performed on the surface ultrastructure of metacercariae and adults of Metagonimus takahashii. Metacercariae were collected from the scale of crucian carp (Carassius auratus) , and adult flukes were harvested 1-4 weeks after infection to rats. In excysted metacercariae. the oral sucker had type I (numerous) and type II (seven in total) sensory papillae. Tegumental spines were dense and digitated into 5-7 points on the surface anterior to the ventral sucker, but became sparse and less digitated posteriorly toward the end of the body In adults, seven type II sensory papillae were characteristically arranged around the lip of the oral sucker, and on the inner side of the lip four small and two large type I sensory papillae were symmetrically seen on each side (12 in total). Tegumental spines on anterior two-thirds of the body. were digitated with 9-12 tips ventrally and 8-13 tips dorsally. Sperms entering into the Laurer's canal were observed. The results show that the surface ultrastructure of M. takuhashii is generally similar to those of M. yokogawai and M. miyatai except for the digitation of tegumental spines.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.249-257
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• 2009

A survey was performed to investigate the infection status of fishborne trematode (FBT) metacercariae in freshwater fish from Guangxi Zhuang Autonomous Region, China. A total of 307 freshwater fish of 31 species were collected from 5 administrative regions of Guangxi Zhuang Autonomous Region. They were examined by artificial digestion method from July 2003 to August 2004. No metacercariae were detected in fish from Fusui-xian. In fish from Mashan-xian and a market in Nanning, 3 species of metacercariae, Haplorchis taichui, Haplorchis pumilio, and Centrocestus formosanus, were mainly detected. Metacercariae (8 in number) of Clonorchis sinensis were found in 1 Chanodichthys dabryi purchased from a market in Nanning. In fish from Yangshuo, Metagonimus yokogawai metacercariae were detected from all 18 fish species examined. Total 13 C. sinensis metacercariae were found in 3 out of 10 Hemibarbus maculatus from Yangshuo. All7 Zacco platypus from Yangshuo were infected with 8-112 Echinochasmus perfoliatus metacercariae. In fish from Binyang-xian, H. pumilo metacercariae were mainly detected in all 5 fish species examined, and only 1 metacercaria of C. sinensis was found in a Hemiculter leucisculus. From the above results, it was confirmed that some species of freshwater fish play a role of second intermediate hosts for FBT in Guangxi Zhuang Autonomous Region, China. In particular, 4 species of intestinal flukes, M. yokogawai, H. taichui, H. pumilio, and C. formosanus, were prevalent in fish hosts, whereas C.sinensis metacercariae were detected only in 3 fish species.

• 대한의생명과학회지
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• 제10권3호
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• pp.219-230
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• 2004

This experiment was performed to examine the in vitro and in vivo affects of the two different haplotype strains of mice, BALB/c and C3H/HeN infected with Echinostoma hortense, and the manifestation of the profiles of cytokine in the splenocytes. In the in vitro experiment, the two mice's splenocytes were divided and stimulated with antigen of crude extracts and the antigen of excretory and secretory products of an adult warm and the manifestation of cytokine mRNA was verified with RT-PCR. As a result, the two different strains of mice both strongly manifested the Th2 cytokine rather than the Thl cytokine and in the case of the Th2 cytokine, the BALB/c mice manifested more strongly than the C3H/HeN mice. In the experiment using the ELISA method, the protem cytokine manifestation had the same result as the mRNA experiment. In the in vivo experiment, the mice was infected via oral route with the metacercaria of the Echinostoma hortense and the manifestation of cytokine was verified by RT-PCR and ELISA and the results were the same as the in vitro experiment. Therefore, in the two strains of BALB/c and C3H/HeN, the C3H/HeN showed a higher susceptivity to the Echinostoma hortense.

• Parasites, Hosts and Diseases
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• 제48권1호
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• pp.49-55
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• 2010

In vitro cultivation of trematodes would assist studies on the basic biology of the parasites and their hosts. This is the first study to use the yolk of unfertilized chicken eggs as a simple and successful method of ovocultivation and the first time to obtain the adult-stage of the trematode Cymatocarpus solearis Braun, 1899 (Digenea: Brachycoeliidae). Chicken eggs were inoculated with metacercariae from the muscle of the spiny lobster, Panulirus argus (Latreille, 1804). The metacercariae were excysted and incubated for 576 hr (24 days) at $38^{\circ}C$ to obtain the adult stage. Eggs in utero were normal in shape and light brown color. The metacercariae developed into mature parasites that have been identified as the adultstage found in marine turtles. The adult lobsters collected in Quintana Roo State, Mexico, showed the prevalence of 49.4% and the mean intensity of 26.0 per host (n=87). A statistical study was performed to determine that no parasitic preference was detected for male versus female parasitized lobsters. Morphometric measurements of the adult-stage of C. solearis obtained in our study have been deposited in the National Helminths Collection of the Institute of Biology of the National Autonomous University of Mexico. This study is significant because it is the first time that a digenean of the family Brachycoeliidae has been demonstrated to develop in vitro from metacercariae into adults capable of producing eggs using the yolk of unfertilized chicken eggs. Secondly, this technique allows to obtain the adult stage of C. solearis without the presence of its marine turtle host, allows us to describe the mature parasites, and thus contribute to our understanding of the biology of C. solearis.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.683-687
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• 2013

Among Paragonimus species, P. paishuihoensis is one of the most mysterious and poorly understood species. Metacercariae are characterized by having a unique dendritically branched excretory bladder. However, the morphology of the adult worm remains unknown. To date, metacercariae of this species have been reported only in China and Thailand. In this study, we first found P. paishuihoensis metacercariae in freshwater crabs, Potamon lipkei, in Hinheub District, Vientiane, Lao PDR, with a prevalence of 77.7% and the average intensity of 10.3 (range 1-28) metacercariae per crab. The molecular data based on ITS2 and CO1 markers indicated that P. paishuihoensis from Laos and Thailand were almost completely identical and were close to members of the Paragonimus bangkokensis/Paragonimus harinasutai complex. Attempts to infect experimental animals (cats, dogs, and rats) with P. paishuihoensis were unsuccessful, suggesting that these animals might be unsuitable definitive hosts for the species. Further studies are necessary to elucidate the taxonomic status and life cycle of P. paishuihoensis.