Abstract
To study the basic pathological changes of small intestine in metagonimiasis, light- and electron microscopic studies were made, using a total of 21 cats which were experimentally infected with metacercariae of Metagonimus yokogawai. The metacercariae were obtained from naturally infected sweetfish (Plecoglossus altivelis) by digestion technique. The cats were divided in control, light-infection(10,000 metacercariae infected) and heavy-infection(50,000 metacercariae infected) groups. Cats were killed at the 5th, 10th, 15th day, and 4th, 8th and 10th week after the infection. And the small intestine was prepared for the study. Pathological studies comprised gross examination, worm distribution pattern, light microscopic examination and both transmission and scanning electron microscopic examinations. The results obtained were summarized as follows. Gross morphologic changes were the most marked during the first 2 weeks after infection. The gross abnormalities were severer in the heavily infected animals. The changes were dryness and listlessness of serosal surface due to dehydration, mushy and/or watery intestinal content, effacement of transverse nodes and enlargement of mesenteric lymph folds and Peyer's patches.
After 4 weeks of infection, these changes became less marked showing a tendency to return to normal. The sectioned flukes were distributed from duodenum to proximal ileum. However, individual variation was marked in distribution. In the heavy-infection group, the locality of parasitism tended to extend more distally. The locality of M. yokogawai in the intervillous space was mostly in the lower-most portion of intervillous space, where they compressed and eroded epithelial cells probably due to mechanical damage to the structure. Very rarely the worms were found in lumen of Lierberkuehn's crypt, and reaching, in two occasions, into proprial lymphoid tissue. Light-microscopically the lesion was restricted in mucosa: Early mucosal changes were shortening, blunting, fusion, and thickening of the villi, crypt hypertrophy with consequent decrease of villus/crypt ratio, as well as stromal changes of edema, capilliary ectasia and marked inflammatory cell infiltration of lymphocytes and plasma cells. Goblet cells were markedly reduced in number as with depletion of its cytoplasmic content. In the later stages of infection, mucosa restored its normal configuration in spite of persistent parasitism of the worms. At the infection stage of 5-15 days, there was significant shortening of the microvillous height with varible destruction of glycocalyx in electron microscopic examination. With lapse of infection time, microvilli became to restore the normal pattern. With these morphological changes, it appears that diarrhea in experimental metagonimiasis would be related to the decrease of absorptive surface of the small intestine particularly in the early phase of infection. The significant changes seen in villi and microvilli might be due to massive intrusion or invasion of Metagonimus worms into the crypts, causing direct mechanical and possible host-immune response to the small bowel mucosa.
Citations
Citations to this article as recorded by
- Intestinal histological alterations in farmed red-bellied pacu Piaractus brachypomus (Characiformes: Serrasalmidae) heavily infected by roundworms
Ruben C. Cuadros, Norma L. S. Rivadeneyra, Anai Flores-Gonzales, Omar Mertins, Jose C.O. Malta, M. Enrique Serrano-Martínez, Patrick D. Mathews
Aquaculture International.2021; 29(3): 989. CrossRef - Fishborne zoonotic heterophyid infections: An update
Jong-Yil Chai, Bong-Kwang Jung
Food and Waterborne Parasitology.2017; 8-9: 33. CrossRef - Population dynamics and host reactions in young foxes following experimental infection with the minute intestinal fluke, Haplorchis pumilio
Sofie Nissen, Stig Milan Thamsborg, Per Walther Kania, Páll S Leifsson, Anders Dalsgaard, Maria Vang Johansen
Parasites & Vectors.2013;[Epub] CrossRef - Foodborne Intestinal Flukes in Southeast Asia
Jong-Yil Chai, Eun-Hee Shin, Soon-Hyung Lee, Han-Jong Rim
The Korean Journal of Parasitology.2009; 47(Suppl): S69. CrossRef - Food-borne intestinal trematode infections in the Republic of Korea
Jong-Yil Chai, Soon-Hyung Lee
Parasitology International.2002; 51(2): 129. CrossRef - A review of Gymnophalloides seoi (Digenea: Gymnophallidae) and human infections in the Republic of Korea
Soon-Hyung Lee, Jong-Yil Chai
The Korean Journal of Parasitology.2001; 39(2): 85. CrossRef - Intestinal histopathology and in situ postures of Gymnophalloides seoi in experimentally infected mice
Jong-Yil Chai, Hong-Soon Lee, Sung-Jong Hong, Jae Hyung Yoo, Sang-Mee Guk, Min Seo, Min-Ho Choi, Soon-Hyung Lee
The Korean Journal of Parasitology.2001; 39(1): 31. CrossRef - Invasion of Metagonimus yokogawai into the submucosal layer of the small intestine of immunosuppressed mice
J Y Chai, J Kim, S H Lee
The Korean Journal of Parasitology.1995; 33(4): 313. CrossRef - Chronological observation on intestinal histopathology and intraepithelial lymphocytes in the intestine of rats infected with Metagonimus yokogawai
J Y Chai, T Y Yun, J Kim, S Huh, M H Choi, S H Lee
The Korean Journal of Parasitology.1994; 32(4): 215. CrossRef - Antigenic localities in the tissues of Metagonimus yokogawai in the period of growth
H J Rim, S J Kim, M G Yang
The Korean Journal of Parasitology.1992; 30(4): 309. CrossRef - Activities of brush border membrane bound enzymes of the small intestine in Metagonimus yokogawai infection in mice
S T Hong, J R Yu, N H Myong, J Y Chai, S H Lee
The Korean Journal of Parasitology.1991; 29(1): 9. CrossRef - Antigenic localities in the tissues of Metagonimus yokogawai observed by immunogoldlabeling method
H Ahn, H J Rim, S J Kim
The Korean Journal of Parasitology.1991; 29(3): 245. CrossRef - Intestinal trematodes of humans in Korea: Metagonimus, heterophyids and echinostomes
J Y Chai, S H Lee
The Korean Journal of Parasitology.1990; 28(Suppl): s103. CrossRef - Observation of mucosal pathology after praziquantel treatment in experimental Fibricola seoulensis infection in rats
S H Lee, B I Kim, S T Hong, W M Sohn, J Y Chai
The Korean Journal of Parasitology.1989; 27(1): 35. CrossRef - Specific IgG antibody responses in experimental cat metagonimiasis
Seung Yull Cho, Suk Il Kim, Shin Yong Kang
The Korean Journal of Parasitology.1987; 25(2): 149. CrossRef - Studies on the intestinal fluke, Metagonimus yokogawai Katsurada, 1912 in Korea Geographical distribution of sweetfish and infection status with Metagonimus metacercaria in south-eastern area of Korea
Chul Yong Song, Soon Hyung Lee, Sang Rin Jeon
The Korean Journal of Parasitology.1985; 23(1): 123. CrossRef - A preliminary observation on watery content of small intestine in Metagonimus yokogawai infected dog
SY Cho, SI Kim, YE Earm, WK Ho
The Korean Journal of Parasitology.1985; 23(1): 175. CrossRef - A histopathological study on the intestine of mice and rats experimentally infected by Fibricola Seoulensis
Soon Hyung Lee, Byong Hoon Yoo, Sung Tae Hong, Jong Yil Chai, Byong Seol Seo, Je Geun Chi
The Korean Journal of Parasitology.1985; 23(1): 58. CrossRef - Study on Metagonimus yokogawai(Katsurada, 1912) in Korea VII. Electron microscopic observation on the tegumental structure
Soon Hyung Lee, Byong Seol Seo, Jong Yil Chai, Sung Jong Hong
The Korean Journal of Parasitology.1984; 22(1): 1. CrossRef - A study on intestinal lesions of experimentally reinfected dogs with Metagonimus yokogawai
Shin Yong Kang, Seung Yull Cho, Jong Yil Chai, Jung Bin Lee, Du Hwan Jang
The Korean Journal of Parasitology.1983; 21(1): 58. CrossRef
