Maintenance of Schistosomatium douthitti (Cort, 1914) in the Laboratory (Trematoda: Schistosomatidae)

Publisher Website
Google Scholar
Abstract
Descriptions of methods employed to maintain S. douthitti in the laboratory, rearing the snail intermediate hosts, Lymnaea stagnalis appressa and L. palustris. obtaining miracidia from feces and liver tissues, infecting young snails, obtaining cercariae from infected snails, exposing mice, hamsters, rabbits and monkeys to quantitative doses of cercariae, and a rapid method for the recovery of worms are outlined. The longevity of 61 infected snails 17-29 days old at time of exposure and 12 snails 149 days old at exposure was for some of the former 515 days and for the latter 315 days. Of 1764 snails exposed in Illinois and Pennsylvania to several miracidia each, 23.4% of 1952 survivors became infected; for 381 snails exposed to 3-5 miracidia in Florida, 299 survived and 83.6% were infected. The sex of cercariae for 36 naturally infected snails, 113 snails exposed to 5-10 miracidia and 90 snails exposed to one miracidium each was determined by infection in mice. Naturally infected and laboratory infected (multiple miracidia) yielded male infections 41% and 45%, respectively; female infections 27% and 23%, respectively; male and female infections 30% and 31%, respectively. For snails exposed to one miracidium 57.7% harbored male and 42.3% female infections. 116 snails infected with one miracidium each began shedding cercariae 37-52 days after exposure. Normal male and female worms have been recovered from mice infected 383 days; female worms from infections 468-484 days old; and male worms after 828 days. Mice and hamsters are very susceptible hosts; rats and rabbits are more resistant. Infections in monkeys persist for only 2-3 weeks. In 479 mice (CF1, C3H and dba strains) exposed to 22,393 cercariae 49.21% developed into mature worms. Mean number of worms recovered from a group of 303 CF1 mice exposed to 50 cercariae each was 25.08.
Keywords