Product News: Using Cellular Impedance to Tackle Parasites

The frustration of staring down a microscope to count the number of times a worm wiggles has inspired an innovative test that could help win the war against human parasites.

James Cook University (JCU) researchers and American colleagues from ACEA Biosciences and George Washington University have developed the xWORM test which is a fast and accurate way of measuring whether parasitic worms are dead or alive after being exposed to a drug.

Dr. Michael Smout from JCU’s Australian Institute of Tropical Health and Medicine (AITHM) said the greatest challenge for parasitologists has been how to accurately and efficiently test the effectiveness of various drugs against parasitic worms.

“We were looking for a fast economical way to do that on a large scale and realised the solution was staring us in the face when we observed a beleaguered student counting worm wiggles down the microscope,” he said.

Dr. Smout and his colleagues adapted the xCELLigence® Real-Time Cell Analysis (RTCA) system, developed by ACEA Biosciences, which is more commonly used for tasks such as monitoring cell proliferation and death in cancer research. 

“We found we could place parasitic worms into the wells of ACEA’s electronic plates (E-Plates®) that contain gold microelectrodes, add a drug treatment and then use the xCELLigence® RTCA system to read the motility or amount of worm wiggle,” he said.

“Basically the trace from the xCELLigence® RTCA system tells us how the worms are affected by the drug by monitoring whether they are alive, sick or dead without someone having to be there doing the time-consuming work counting thousands of worm wiggles down the microscope.”

“It is a drop dead easy solution for speeding up the process to find new treatments for eliminating insidious parasitic worms that plague humanity and animals alike - infecting more than 1 billion people worldwide and killing hundreds of thousands annually.”

“It is also a cost-effective solution as the E-Plate® can be re-used for this worm motility assay, meaning it costs only USD$0.05 to perform each test.”

Working with the ACEA Biosciences team, the JCU researchers have optimized the xCELLigence® RTCA protocol for parasitic worms and dubbed it xWORM (xCELLigence Worm Real-time Motility Assay). 

Dr. Smout said the xWORM assay has broad applications for studying parasitic worms. His lab has used it to study multiple life cycle stages of the blood fluke parasite Schistosoma mansoni, which warning signs in tropical tourist hotspots label as bilharzia or snail fever.

 “This parasite and related species can infect humans and animals exposed to slow moving or stagnant water that contains specific snail species in many regions of the world including Egypt, Brazil, and many parts of Asia,” he said.

Although this parasite motility assay was not a use originally envisaged for the xCELLigence® RTCA system, ACEA’s Vice-President Yama Abassi welcomed it enthusiastically. “The most innovative applications come from our users,” he said.  Abassi further noted that the xWORM assay provides “further evidence of the sensitivity and flexibility of our impedance-based technology for studying phenomena that were previously inaccessible or very laborious, costly and inefficient to study.”

Dr Smout said the xWORM test added another weapon to the arsenal of researchers in the global war against parasitic worms.