L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 5. 1989 (Budapest, 1989)

Sey, O.: Laboratory model for studying experimental fascoilopsiosis

Laboratory model for studying experimental fasciolopsiosis By O. SEY (Received September 12, 1988) ABSTRACT. Eggs of Fasciolopsis buski for experimental examination of fasciolopsiosis were obtained from feces of artificially infected pig by several sieving and washing. Embryonic development, lasted 15 days at 30°C and hatching of miracidia was stimulated by low energy of light. Intermediate host, Segmentina hemisphaerula proved to be susceptible and the take varied between 25 and 46 per cent. Intramulluscan development lasted 60 days post infection at room temperature. Prépaient period was 50-65 days, peak of egg-production between 90-120 days (.3 000-4 500 EPG) and later it decreased gradually. KEY WORDS: Fasciolopsis buski (Trematoda), life cycle, Segmentina hemisphaerula (Mollusca) Fasciolopsis buski (Lankester, 1857), the giant intestinal fluke, is a parasite of man and hog in several South - and South-East Asian countries. While particular attention has been paid to fasciolopsiosis of man in the endemic areas, fasciolopsiosis of pigs, however, had a relatively little room for examinations. Those examinations, dealing with the life-cycle of this fluke, have usually used metacercariae, derived from naturally infected snails. Thus, several methodological details were left out of considerations which are necessary to propagate metacercariae in appropriate time and quality for artificial infestations. The present report is concerned with laboratory observations on the complete life-cycle of this fluke. MATERIAL AND METHODS The original stock of metacercariae of F. buski and that of the intermediate snail hosts (Segmentina hemisphaerula O.F. Müller, 1774) were collected by the author during his visit in Vietnam, Hanoi district. Three piglets, two months old, were infected with 1 000 metacercariae each, and they served as donors for further examinations. Eggs were recovered from the fresh feces by dilution with water (1: 4) and by subsequent sieving. The pore aperture of the last sieve was not more than 0.04 mm. The material retained in the sieve was washed with water into Petri dishes. Eggs were incubated in thermostate at 30°C. Regular aquaria of 3 to 5 liters capacity, provided with airation, were used for breeding and holding the snails. Dechlorinated tap water was applied, it was changed twice a week. Newly hatdhed snails were fed on green algae, cultivated separately; older ones were fed on fresh or boiled and dried lettuce.