A rotifer-derived paralytic compound prevents transmission of schistosomiasis to a mammalian host

by Jiarong Gao, Ning Yang, Fred A. Lewis, Peter Yau, James J. Collins III, Jonathan V. Sweedler, Phillip A. Newmark Schistosomes are parasitic flatworms that infect over 200 million people, causing the neglected tropical disease, schistosomiasis. A single drug, praziquantel, is used to treat schistosome infection. Limitations in mass drug administration programs and the emergence of schistosomiasis in nontropic al areas indicate the need for new strategies to prevent infection. It has been known for several decades that rotifers colonizing the schistosome's snail intermediate host produce a water-soluble factor that paralyzes cercariae, the life cycle stage infecting humans. In spite of its potential for p reventing infection, the nature of this factor has remained obscure. Here, we report the purification and chemical characterization of Schistosome Paralysis Factor (SPF), a novel tetracyclic alkaloid produced by the rotiferRotaria rotatoria. We show that this compound paralyzes schistosome cercariae and prevents infection and does so more effectively than analogous compounds. This molecule provides new directions for understanding cercariae motility and new strategies for preventing schistosome infection.
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research