Infectivity Assay for Giardia Lamblia Cysts
Cysts of the protozoan parasite Giardia lamblia are found worldwide in surface water, in wastewater, and in treatment plant effluents. If ingested, infectious cysts release a trophozoite that can initiate an infection by colonizing the small intestine and dividing to high numbers. Immunofluorescence assays that are routinely used to microscopically detect cysts in water concentrates or fecal samples do not differentiate between infectious cysts and cysts that are unable to cause an infection. In experimental settings, laboratory rodents are needed to assess infectivity, but this approach is not practical for water monitoring. The project developed a molecular assay that can rapidly discriminate between infectious cysts and cysts unable to cause an infection. Messenger RNA (mRNA) was evaluated as a molecular marker of infectivity.
Originally funded as WERF project Reuse-08-18.