Existense of Replicating Sporocysts in the Development Cycle of Schistosoma haematobium

Abstract

1 ml) to a Petri dish, and counted under a dissecting microscope. The larvae were classified initially as tailed and tailless larvae, and we noted if organisms were living or dead. To separate cercarial bodies, which remain alive in fresh water, from schistosomules, which die under such conditions, 5 ml of distilled water was dropped into the Petri dish containing the larvae, and after 10 min the live and dead larvae were recounted. In the first counting (in saline), the larvae from oxamniquine-treated animals were recovered in different percentages from those from the controls. However, the bodies of many tailed, live organisms were more flexible than those of cercariae and did not show the usual pattern. Surprisingly, after exposure to water, the numbers of cercaria-like, tailed organisms that were alive in the first counting were cut by about 50% (Table I). It was assumed that the additional time required for such procedures affected neither mortality nor the transformation process. Death of cercaria-like tailed organisms was then attributed to water sensitivity. In order to see if the vehicle affected the cercaria-schistosomule transformation, a group of five animals receiving only PEG was compared with other control group. No differences were seen between those groups. We propose that 4,000 mg/kg doses of oxamniquine inhibited cercarial decaudation, but the progressive loss of the glycocalyx was not inhibited by this compound.