The metacercariae of Acanthotrema felis Sohn et al., 2003 (Digenea: Heterophyidae) were discovered in a species of the brackish water fish, Acanthogobius flavimanus, in the Republic of Korea. They were experimentally fed to kittens, and adult flukes were harvested 7 days later. The adults were morphologically characterized by the presence of a bipartite seminal vesicle, the ventral sucker associated with a ventrogenital sac enclosing 3 sclerites (2 long and pointed, and 1 short and thumb-like), and an unarmed gonotyl. The adult flukes were identified as A. felis Sohn et al., 2003, and the brackish water fish A. flavimanus has been verified as one of its second intermediate hosts.
Animals ; Cats/parasitology ; Fishes/*parasitology ; Histocytochemistry/veterinary ; Intestinal Diseases, Parasitic/parasitology/pathology/veterinary ; Korea ; Trematoda/anatomy & histology/*growth & development ; Trematode Infections/parasitology/pathology/veterinary

A 65-year old Korean man, living in Mokpo-city, Jeollanam-do, Republic of Korea, visited a local clinic complaining of right upper quadrant pain and indigestion. At colonoscopy, he was diagnosed as having a carcinoma of the ascending colon, and thus, a palliative right hemicolectomy was performed. Subsequently, an adult fluke of Gymnophalloides seoi was incidentally found in a surgical pathology specimen of the lymph node around the colon. The worm was found to have invaded gut lymphoid tissue, with characteristic morphologies of a large oral sucker, a small ventral sucker, and a ventral pit surrounded by strong muscle fibers. This is the first reported case of mucosal tissue invasion by G. seoi in the human intestinal tract.
Trematode Infections/diagnosis/parasitology/*pathology ; Trematoda/*isolation & purification/ultrastructure ; Male ; Lymphoid Tissue/*parasitology ; Korea ; Intestinal Diseases, Parasitic/diagnosis/*parasitology/pathology ; Humans ; Colonic Diseases/*parasitology ; Colon/*parasitology/pathology/surgery ; Animals ; Aged

Maritrema spp. (Digenea: Microphallidae) are parasites of birds, but have not been found in the Republic of Korea. In this study, metacercariae of Maritrema sp. were discovered in the Asian shore crab, Hemigrapsus sanguineus, caught in the mud-flats of Jebu-do, Hwasung-gun, Gyeonggi-do, and the adult flukes were confirmed by experimental infection into mice. Based on the symmetric ribbon-like vitellarium, adult flukes of Maritrema sp. were identified, but did not belong to previously described species in terms of the following morphologic characteristics: ceca reaching to the lateral wall at the anterior border of the ovary; ventral sucker larger than oral sucker; a prominent metraterm; and vitellarium forming a complete ring. Hence, we named this microphallid M. jebuensis n. sp. after the island where the second intermediate hosts were collected. From this study, it has been shown that Maritrema sp. is distributed in Korea and transmitted by the Asian shore crab, H. sanguineus.
Animals ; Brachyura/*parasitology ; Disease Models, Animal ; Metacercariae/anatomy & histology/isolation & purification ; Mice ; Mice, Inbred ICR ; Republic of Korea ; Trematoda/anatomy & histology/*classification/*isolation & purification ; Trematode Infections/parasitology/pathology

In the present study, we evaluated the histological morphology of the adult Paramphistomum (P.) gracile. Adult flukes with bodies 5~15 mm in length and 2~7 mm in width were subjected to histological analysis. Longitudinal and transversal serial-sections were stained with hematoxylin and eosin, and examined. The body surface and longitudinal section of P. gracile were also assessed using scanning electron microscopy. In this species, the anterior sucker and posterior sucker (acetabulum) were present on an anterior and posterior part of the body, respectively. The major folds were located in the areas of the anterior sucker, genital canal, and posterior sucker. The fluke membrane was spineless at the tegument surface and in the tegument tissue. Histological data showed structural-systematic characteristics of the digestive tract, reproductive tract, excretory tract, copulatory organs, connective tissues, and muscle tissues. We attempted to elucidate the histological characteristics of P. gracile that might increase the knowledge and understanding of rumen fluke morphology.
Animals ; Cattle ; Cattle Diseases/*parasitology/pathology ; Female ; Male ; Microscopy, Electron, Scanning/veterinary ; Rumen/parasitology ; Stomach Diseases/parasitology/pathology/*veterinary ; Thailand ; Trematoda/*anatomy & histology/isolation & purification/ultrastructure ; Trematode Infections/parasitology/pathology/*veterinary

A 33-year-old Korean man visited a medical clinic with complaints of throat discomfort and pain for one week. The symptoms occurred one day after eating raw brackish water fish, perch. Endoscopy revealed a fluke, about 5 mm in length, attaching to and peristaltically moving on the surface of the mucosa at the arytenoid region of the larynx. Microscopically, the testes were triangular, tandem, and separated by the uterus. The ovary and cirrus pouch were placed apart from median line between testes. Numerous blood cells were observed in the ceca. The worm was identified to be Clinostomum complanatum. This is the second human case of clinostomiasis in Korea.
Adult ; Animal Structures/anatomy & histology ; Animals ; Endoscopy ; Foodborne Diseases/*diagnosis/parasitology ; Humans ; Korea ; Larynx/parasitology/pathology ; Male ; Microscopy ; Pharynx/parasitology/pathology ; Trematoda/anatomy & histology/*isolation & purification ; Trematode Infections/*diagnosis/parasitology

The intestinal histopathology and in situ postures of Gymnophalloides seoi (Digenea: Gymnophallidae) were studied using C3H/HeN and C57BL/6 mice as experimental hosts; the effects of immunosuppression were also observed. The metacercariae isolated from naturally infected oysters, 300 or 1,000 in number, were infected orally to each mouse, and the mice were killed at days 3-21 post-infection (PI). In immunocompetent (IC) mice, only a small number of flukes were found in the mucosa of the duodenum and jejunum during days 3-7 PI, with their large oral suckers pinching and sucking the root of villi. The intestinal mucosa showed mild villous atrophy, crypt hyperplasia, and inflammations in the villous stroma and crypt, with remarkable goblet cell hyperplasia. These mucosal changes were almost restored after days 14-21 PI. In immunosuppressed (IS) mice, displacement as well as complete loss of villi adjacent to the flukes was frequently encountered, otherwise the histopathology was generally mild, with minimal goblet cell hyperplasia. In these mice, numerous flukes were found, and it seemed that they were actively moving and rotating in situ. Several flukes were found to have invaded into the submucosa, almost facing the serosa. These results indicate that in IC mice the intestinal histopathology caused by G. seoi is generally mild, and the flukes do not penetrate beyond the mucosa, however, in IS mice, the flukes can cause severe destruction of neighboring villi, and some of them invade into the submucosa.
Animals ; Atrophy ; Immunocompromised Host ; Intestinal Diseases, Parasitic/*parasitology/pathology ; Intestinal Mucosa/parasitology/*pathology ; Male ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; Support, Non-U.S. Gov't ; Trematoda/*pathogenicity ; Trematode Infections/*parasitology/pathology

In November 2007, a 46-year-old male Thai patient presented with chronic abdominal pain for over 3 years. Colonoscopy revealed a small parasite of about 2 x 1 mm in size attached to the cecum mucosa. The worm was removed endoscopically, fixed, and stained for morphological observations. The specimen was identified as Anchitrema sanguineum (Digenea: Anchitrematidae), a trematode first reported in a reptile, Chamaeleo vulgaris, from Egypt, and then sporadically found in the intestines of insectivorous bats and other mammals. The patient was treated with praziquantel but no more worms were found in his stool. His symptoms improved slightly but not cured completely. It remains unclear whether the chronic abdominal pain of the patient was caused by this trematode infection. Whatever is the pathogenicity of this trematode, this is the first human case of A. sanguineum infection in the literature.
Abdominal Pain/*etiology ; Animals ; Antiprotozoal Agents/therapeutic use ; Cecum/parasitology ; Colonoscopy ; Humans ; Intestinal Mucosa/parasitology ; Male ; Middle Aged ; Praziquantel/therapeutic use ; Thailand ; Trematoda/*isolation & purification ; Trematode Infections/*diagnosis/drug therapy/pathology

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.
Animals ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Goblet Cells/immunology ; Heterophyidae/*immunology ; *Immunity, Mucosal ; Immunoglobulin A/analysis ; Intestine, Small/parasitology/pathology ; Leukocyte Count ; Lymphocytes/immunology ; Male ; Mast Cells/immunology ; Mice ; Mice, Inbred ICR ; Parasite Load ; Time Factors ; Trematode Infections/*immunology/parasitology