U.S – The Center for Produce Safety (CPS) is now funding two research projects aimed at advancing Cyclospora cayetanensis detection and management techniques.
C. cayetanensis is a sophisticated protozoan parasite that is very difficult to culture in a lab setting and requires intricate microscopy to find in samples.
The goal of the first research, which is being overseen by Lia Stanciu, Ph.D. of Purdue University, is to employ “aptamers,” or brief strands of manufactured DNA, to bond to C. cayetanensis.
Then, using the aptamers, a paper-based, inexpensive, and simple-to-use water test for the parasite will be developed, comparable to a fast COVID-19 or pregnancy test.
The scientists were able to discover certain proteins on the parasite’s cell membrane that are uniquely present in C. cayetanensis and to which specific DNA sequences can bind.
Such DNA-specific compounds might be produced and included in a quick test for use in the field.
The microfluidic paper-based tests will change color when exposed to C. cayetanensis oocysts in a water sample, with pink denoting a positive result and purple denoting a negative result.
The test will be put within a tiny, transportable image processing machine that can read the test’s color and transmit the results.
The next step for the researchers is to use C. cayetanensis samples from specialized labs connected to the U.S. Food and Drug Administration to confirm their paper-based testing system.
Using zero-valent iron sand filters to manage C. cayetanensis
Using zero-valent iron (ZVI) sand filters to remove C. cayetanensis from water is the subject of the second study, which is examining the possibility of physical exclusion as a means of lowering parasite burdens.
The project is led by Benjamin Rosenthal, S.D. with the U.S. Department of Agriculture’s Agricultural Research Service (USDA’s ARS).
Jitender Dubey, Mark Jenkins, and Manan Sharma of the USDA ARS, as well as Kalmia Kniel and Kalmia Kniel of the University of Delaware, are all co-principal investigators alongside Dr. Rosenthal.
The current experiment is based on earlier research Drs. Kniel and Sharma did on filtration to lower bacterial and viral infections in water.
The researchers will substitute Eimeria as a C. cayetanensis for proof-of-concept testing.
The chicken parasite Eimeria is easily accessible and safe for people to handle. It is a close relative of C. cayetanensis.
In their initial lab tests, the researchers injected water with a predetermined amount of Eimeria, ran it through a PVC tube that was filled with sand to mimic a sand filter, and then assessed the parasite decrease in the outflow.
Although the results were positive, only around 80% of the original Eimeria population was recovered when the researchers back-flushed the temporary filters.
The experiment was subsequently replicated using a filter made of 50% sand and 50% ZVI, and the researchers discovered a similar decline in parasites in the outflow.
However, very few Eimeria were found when the researchers back-flushed the ZVI medium.
The scientists intend to whirl Eimeria in a ZVI and water mix to see if ZVI affects the infection physically in addition to merely sand.
The parasite will then be inspected for damage, fed to hens, and its viability and virulence determined.