• 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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• 제30권2호
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• pp.75-82
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• 1992

Heterophyes necens의 표피 미세구조를 주사전자현미경으로 관찰하였다. 충체는 실험 감염시킨 고양이에서 얻은 성충과 인체 자연감염자에서 회수한 성충을 재료로 하였다. 충체는 나뭇잎 모양이며 복측으로 약간 굽어 있었고, 유원형 또는 서양배 모양이며 전반부는 등글고 후반부로 갈수록 충체의 폭이 차츰 감소하였다. 구흡반 주위에는 짧은 섬모가 있는 제 I형 감각유두가 4∼5개씩 모인 군집 감각유두가 관찰되었으며 그 사이 사이에 단일 감각유두가 분포하였다. 구흡반 외연 및 직후방에는 5∼9개의 분지를 가진 피극이, 구흡반과 복흡반 사이에는 12∼17개의 분지를 가진 피극이 분포하였다 복흡반의 구순에는 표피가 둥글게 융기한 제 II형 감각유두가 7∼8 개 일정 간격으로 위치하였다. 구흡반과 복흡반 사이에는 우측과 좌측에 각각 5개 및 6개의 감각유두로 구성된 군집 감각유두가 3개군씩 대칭적으로 배열되어 있었고 그 사이에 단일 감각유두가 분포하였다. 고양이에서 회수한 성충의 생식반은 흔히 함몰되거나 약간만 돌출되어 있어 gonotyl spine을 관찰하기 어려웠으나, 환자에서 얻은 성충은 대부분의 경우 생식반이 충체 바깥으로 돌출되어 있었고, gonotyl spine의 수는50∼60개이었다. 복흡반 외측 및 후방에는 8∼12개의 분지를 가진 피극이 각각 관찰되었으며, 충체의 후반부로 갈수록 피극의 분지 수가 점차 감소하여 후단에서는 1∼3개의 분지를 가진 피극이 관찰되었고 피극의 밀도도 점차 낮아지는 양상을 띠었다. 충체 배측에는 4∼5개의 감각유두가 모인 군집 감각유두 4쌍이 좌우 대칭적으로 배열되어 있었다. 충체 배측의 점반부에는 15∼20개의 분지를 가진 피극이 분포하였고 후반부로 갈수록 분지 양상이 감소하여 배측 후 단에서는 8~12개의 분지를 가진 피극이 관찰되었다. 또, 후반부로 갈수록 피극의 밀도가 점차 낮아지는 양상을 보였다. 이상의 결과로 보아 대. nocens 성충의 표피 미세구조는 다른 이형흡충류의 경우와 비슷하나 생식반 외연에 분포하는 gonotyl Spine의 수가 50∼60개인 점, 전 표피에서 관찰되는 피극 및 감각유두의 특이한 분포 등은 H. nocens의 특징적 소견이라고 생각되었다.

• 한국패류학회지
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• 제30권3호
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• pp.295-298
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• 2014

본 연구는 서해안 새만금 방조제 내만에서 발견된 상괭이의 기생충 감염 사례 보고이다. 상괭이는 수컷으로 연령이 8세로 추정되었다. 기생충은 복강, 두개골 및 폐 등 총 3개 기관에서 3종류가 발견되었다. 복강내 선충은 Crassicauda sp.으로 추정되었다. 두개골내 흡충은 Nasitrema sp., 선충은 Pseudaliids 과에 속하는 폐충의 일종일 것으로 추정되었고 폐충은 폐 조직표본 현미경 검사에서도 발견되었다. 아니사키스 (Anisakis spp.) 는 발견되지 않았다.

• Parasites, Hosts and Diseases
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• 제52권1호
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• pp.27-33
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• 2014

Mucosal immune responses against Pygidiopsis summa (Trematoda: Heterophyidae) infection were studied in ICR mice. Experimental groups consisted of group 1 (uninfected controls), group 2 (infection with 200 metacercariae), and group 3 (immunosuppression with Depo-Medrol and infection with 200 metacercariae). Worms were recovered in the small intestine at days 1, 3, 5, and 7 post-infection (PI). Intestinal intraepithelial lymphocytes (IEL), mast cells, and goblet cells were counted in intestinal tissue sections stained with Giemsa, astra-blue, and periodic acid-Schiff, respectively. Mucosal IgA levels were measured by ELISA. Expulsion of P. summa from the mouse intestine began to occur from days 3-5 PI which sustained until day 7 PI. The worm expulsion was positively correlated with proliferation of IEL, mast cells, goblet cells, and increase of IgA, although in the case of mast cells significant increase was seen only at day 7 PI. Immunosuppression suppressed all these immune effectors and inhibited worm reduction in the intestine until day 7 PI. The results suggested that various immune effectors which include IEL, goblet cells, mast cells, and IgA play roles in regulating the intestinal mucosal immunity of ICR mice against P. summa infection.

• 한국임상수의학회지
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• 제36권6호
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• pp.330-335
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• 2019

Apharyngostrigea ibis (Trematoda: Strigeidae) were obtained from the small intestine of two black-crowned night herons (Nycticorax nycticorax) and three grey herons (Ardea cinerea jouyi) between July 2006 and September 2018 in Daejeon metropolitan city and Kangwon province, Republic of Korea. The body is covered with a relatively thick cuticle, devoid of spines, and bipartite. The body measures at 2.3-3.33 × 0.86-1.20 mm, and the fore-body is ventrally concave. The oral sucker leads into a short esophagus that is devoid of a muscular pharynx. The worm was studied with a scanning electron microscope for the first time resulting in the detection of a pair of lappets located at the bilateral portion of the oral sucker. This is the first record of A. ibis in the Republic of Korea.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.451-456
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• 2019

Adult specimens of Echinochasmus caninus n. comb. (Verma, 1935) (Trematoda: Echinostomatidae) (syn. Episthmium caninum Yamaguti, 1958) were recovered from 11 riparian people who resided along the Mekong River in Khammouane Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, the cases revealed eggs of Opisthorchis viverrini/minute intestinal flukes, hookworms, and in 2 cases echinostome eggs. To recover the adult helminths, praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose were given and purged with magnesium salts. Various species of trematodes (including O. viverrini and Haplorchis spp.), cestodes, and nematodes were recovered from their diarrheic stools. Among the trematodes, small echinostome flukes (n=42; av. 3.8 specimens per case) of 0.7-1.2 mm in length are subjected in this study. They are morphologically characterized by having 24 collar spines interrupted dorsally and anterior extension of vitellaria from the cirrus sac or genital pore level to the posterior end of the body. Particularly based on this extensive distribution of vitellaria, the specific diagnosis was made as Echinochasmus caninus. The cases were co-infected with various other helminth parasites; thus, clinical manifestations specific for this echinostome infection were difficult to determine. The present paper describes for the first time human E. caninus infections in Lao PDR. Our cases marked the 4-14th human infections with this echinostome around the world following the 3 previous cases reported from Thailand.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.32-35
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• 1999

During the course of studying the helminth fauna from the fishes of the Korean coastal waters, two bucephalid species, Dolichoenterum longissimum Ozaki, 1924 and Prosorhynchus aculeatus Odhner, 1905, were collected from the alimentary canal of the conger eel, Conger myriaster. D. longissimum was characterized by having the ovary between the testes, and 7-8 horn-like projections on the ventral side of rhynchus. P. aculeatus was distinguished from the other species by the location of the mouth or the opening position of the excretory vesicle. These two bucephalid digeneans are new to the Korean fauna.

• 한국환경보건학회지
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• 제30권4호
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• pp.344-346
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• 2004

During a survey of the helminth parasites of fresh water fishes in Willamette River, metacercariae of Neascus spp. were found on examination of muscle, spinal cord, fin and skin of Chiselmouth, Acrocheilus alutaceus. One hundred percent of 19 Chiselmouth examined were found to be infected with digenetic trematodes. The prevalence of infection was higher in muscle, varying from $95\%\;and\;100\%$. Higher levels were present in muscle, such that the $100\%$ level being found in upper anterior, lower anterior and posterior. Small numbers of metacercariae were found on the fin and skin. The commonest sites of infection were the musculature and spinal cord. Intensities of Neascus spp. metacercariae tended to be and high levels in muscle and spinal cord. Those were low levels occurred in the fin and skin. There was a high degree of Neascus spp. in the occurrence of digenetic trematode from Chiselmouth.

• 한국식품위생안전성학회지
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• 제12권4호
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• pp.300-303
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• 1997

The present study was carried out to know the distribution of freshwater mollusk on the chinese liver fluke in the middle of August, 1997 at the upper area of Kyungan stream located in Yongin Kun, Kyungki province. The snails were collected from the shallow and irrigation route in a rural area located along the upper area of Kyungan stream. The snails collected by hand were brought to the laboratory and cercariae naturally shed from the snails, Parafossarulus manchouricus were examined. Parafossarulus manchouricus is medically important intermediated host of the transmission of digenetic trematoda to human. Each snail was placed in aerated tap water for the detection of ceracariae and examined for expelled cercariae. Infection rate of the cercariae of Clonorchis sinensis was 3 (1.5%) among 195 individuals collected in the habitat. The identification of the cercaria of Clonorchis sinensis was performed as described by Komiya and Tajimi.

• Parasites, Hosts and Diseases
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• 제27권4호
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• pp.249-252
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• 1989

Fibricola cratera is a strigeoid trematode indigenous to North America that, heretofore, was known only to infect wild mammals. Herein, it is reported that an experimental inoculation of a human volunteer produced a patellt infection that lasted 40 months. Symptoms of epigastric discomfort, loose stools and flatulence occurred over the first year of infection and ameliorated thereafter. Eggs per gram of stool were low (${\leq}2$) throughout the course of infection and were not detected by the standard technique of formalin-ether concentration. To monitor infection, the entire stool sample was examined each month after sieving through No. 10 (pore size 2 mm) and 100 (pore size $145{\;}{\mu\textrm{m}}$) sieves and collecting eggs on a No. 325 (pore size $45{\;}{\mu\textrm{m}}$) sieve. This is the first report of a North American strigeoid trematode capable of maturing in a human and is only the second species of strigeoid known to do so. The other species is F. seoulensis which has been implicated in 26 human infections in Korea.