Effects of gamma-irradiation on the survival and development of <i>Metagonimus yokogawai</i> metacercariae in rats

, Chai, J Y; , Kim, S J; , Kook, J; , Lee, S H

doi:1995.33.4.297

Korean J Parasito > Volume 33(4):1995 > Article

Original Article


Korean J Parasitol. 1995 Dec;33(4):297-303. English. Published online Dec 20, 1995. http://dx.doi.org/10.3347/kjp.1995.33.4.297
Copyright © 1995 by The Korean Society for Parasitology


Effects of gamma-irradiation on the survival and development of Metagonimus yokogawai metacercariae in rats
Jong-Yil Chai,^*¹Sang-Joon Kim,²Jina Kook,¹ and Soon-Hyung Lee¹
¹Department of Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 110-799, Korea.
²Department of Radiology, Dankook University College of Medicine, Chonan 330-714, Korea.

Received September 14, 1995; Accepted November 15, 1995.
Abstract
To evaluate the feasibility of irradiation as a control measure for metagonimiasis, the metacercariae of Metagonimus yokogawai were irradiated with gamma ray, either after isolation from the sweetfish (Plecoglossus altivelis) or in situ of the fish, and their survival and development in rats were observed at 7 days post-infection. The radiation dose varied from 5 to 100 Gy for the metacercaria-irradiation group and from 5 to 500 Gy for fish-irradiation group. The results showed that the worm recovery rate from the irradiation groups decreased as the radiation dose was increased. Higher doses of radiation were required for the fish-irradiation group to obtain the same results as the metacercaria-irradiation group. The LD50 of the metacercaria-irradiation group was 4.5 Gy, whereas that of the fish- irradiation group 6.2 Gy. A few number of worms which survived until 7 days in rats were severely retarded especially in the growth of their reproductive organs, i.e., complete or partial failure in the development of testes and formation of uterine eggs. The present study revealed that irradiation of sweetfish by 200 Gy is effective to control infectivity as well as development of M. yokogawai metacercaria in rats.

Figures

Figs. 1-4
Fig. 1. A 7-day old adult worm of M. yokogawai recovered from a rat of non-irradiated control group showing its normal body contour, many intrauterine eggs, well-developed ovary, seminal vesicle, seminal receptacle, vitelline follicles, and two testes. Acetocarmine stained. Fig. 2. An age-matched specimen recovered from a rat infected with 100 Gy-irradiated metacercariae (metacercaria-irradiation group) showing no uterine eggs, no vitelline follicles, pooly developed ovary, and only one testis. Acetocarmine stained. Fig. 3. Another age-matched specimen recovered from a rat infected with 200 Gy-irradiated metacercariae (fish-irradiation group) which shows no uterine eggs, no ovary, no vitelline follicles, and two poorly developed testes. The excretory bladder slightly expanded. Acetocarmine stained. Fig. 4. Another specimen recovered from 200 Gy fish-irradiation group showing no eggs and no reproductive organs. The bladder is distended severely. Acetocarmine stained.

^*Bar represents 100 micrometers.

Tables


	Table 1 Recovery rate of M. yokogawai from the rats of metacercaria-irradiation group


	Table 2 Recovery rate of M. yokogawai from the rats of fish-irradiation group


	Table 3 Morphological features of M. yokogawai recovered from the rats infected with normal (non-irradiated control group) or irradiated metacercariae (metacercaria-irradiation group or fish-irradiation group)

References


1.	Bickle QD, Dobinson T, James ER. The effects of gamma-irradiation on migration and survival of Schistosoma mansoni schistosomula in mice. Parasitology 1979;79(2):223–230.

2.	Chai JY, Lee SH. Intestinal trematodes of humans in Korea: Metagonimus, heterophyids and echinostomes. Korean J Parasitol 1990;28 Suppl:103–122.

3.	Contine YM, et al. J Georgia Entomol Soc 1969;4:149–152.

4.	Dean DA, Mangold BL, Lewis FA. Comparison of two strains of Schistosoma mansoni with respect to the sites and kinetics of immune elimination in irradiated cercaria-immunized mice. J Parasitol 1995;81(1):43–47.

5.	Davis R. J Georgia Entomol Soc 1972;7:57–63.

6.	Entrekin DL, Oliver JH Jr, Pound JM. Effects of gamma radiation on development, sterility, fecundity, and sex ratio of Dermanyssus gallinae (DeGeer) (Acari: Dermanyssidae). J Parasitol 1987;73(3):549–554.

7.	Erickson DG. Am J Trop Med Hyg 1965;14(4):574–578.

8.	Djoen TB. J Parasitol 1965;51(2):42.

9.	Dubey JP, Brake RJ, Murrell KD, Fayer R. Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs. Am J Vet Res 1986;47(3):518–522.

*11.*	Hughes DL. Reduction of the pathogenicity of Fasciola hepatica in mice by x-irradiation. Nature 1962;193:1093–1094.

*13.*	Ikeda T, et al. Jpn J Parasitol 1984;33(5):377–384.

*14.*	Lee SH, Park YH, Sohn WM, Hong ST, Chai JY. The effects of gamma irradiation on the survival and development of Clonorchis sinensis metacercariae. Korean J Parasitol 1989;27(3):187–195.

*15.*	Melville C. An apparent beneficial effect of gamma-radiation on the flour mite. Nature 1958;181(4620):1403–1404.

*16.*	Scheller LF, Stump KC, Azad AF. Plasmodium berghei: production and quantitation of hepatic stages derived from irradiated sporozoites in rats and mice. J Parasitol 1995;81(1):58–62.

*17.*	Seo BS, Lee SH, Cho SY, Chai JY, Hong ST, Han IS, Sohn JS, Cho BH, Ahn SR, Lee SK, Chung SC, Kang KS, Shim HS, Hwang IS. An Epidemiologic Study On Clonorchiasis And Metagonimiasis In Riverside Areas In Korea. Korean J Parasitol 1981;19(2):137–150.

*18.*	Villella JB, et al. J Parasitol 1965;51(2):42.