Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 7, 1999
Publication Date: March 1, 2000
Interpretive Summary: Rotifers are microscopic invertebrates found in moist and aqueous environments worldwide. They survive by feeding on microscopic organisms smaller than themselves such as protozoa and algae. Because they are often found in waste water and sewage where pathogenic protozoa are found the present study was designed to determine if they would ingest one species, Cryptosporidium parvum (Cp), under laboratory conditions. Six genera of rotifers, exposed to the oocyst stage of Cp, all ingested oocysts within a few minutes of exposure. Some individuals ingested as many 25 oocysts. The present study was not designed to determine if oocysts were digested, degraded, or otherwise inactivated. Future studies will attempt to make those determinations which could lead to use of these organisms for biological control of this and possibly other parasites.
Six genera of rotifers including Philodina, Monostyla, Epiphanes, Euchlanis, Brachionus, and Asplanchna were exposed to oocysts of Cryptosporidium parvum cleaned of fecal debris. Unstained oocysts and those stained with fluorescein conjugated monoclonal antibody were added to suspensions of viable rotifers and were examined by phase-contrast, differential interference contrast, and fluorescence microscopy. Rotifers of all six genera were observed ingesting oocysts. In the stomachs of Euchlanis and Brachionus up to an estimated 25 oocysts were observed. Euchlanis and Epiphanes were observed excreting boluses containing up to eight oocysts. It was not determined whether rotifers digested or otherwise rendered oocysts nonviable.