Toxoplasma Gon 'n Did It Again (A Microscopic Look at the Behavior of Toxoplasma Gondii)—William J. Sullivan, PhD—Showalter Professor of Pharmacology & Toxicology at Indiana University School of Medicine

Professor and author of Pleased to Meet Me: Genes, Germs, and the Curious Forces That Make Us Who We Are, joins the show for a second time today to discuss parasites, focusing on one in particular that affects a significant number of people: Toxoplasma gondii.

By tuning in, you'll discover the following:

• How Toxoplasma gondii enters a cell and then replicate exponentially
• Why brain tissue is a common place for Toxoplasma gondii to end up, how the parasite behaves once in neurons and nuclei, and how these locations protect it from the host's immune system and drug interventions
• How Toxoplasma gondii initiates a starvation response in a host cell in order to obtain even more food without further effort

As a graduate student at University of Pennsylvania, Dr. Sullivan had already had a longstanding interest in microbiology when he began doing lab rotations that would ultimately help him develop his PhD thesis.

It was during that time that he discovered toxoplasma gondii, microscopic banana-shaped organisms squirming their way through fibroblast cells and growing exponentially until blowing apart the host cell.

At the time, Dr. Sullivan was absolutely fascinated by these organisms, and decided to pursue research on them from there on out. He wanted to know the details of how Toxoplasma gondii functions and how it could be impacting human health, so he was particularly excited to learn that a professor in the lab was working on turning Toxoplasma gondii into one of the first model systems for all of parasitology.

This would allow for modern-day cell and molecular genetic techniques to be employed—a feat impossible for most other parasites. This would pave the way for avenues of unprecedented research in parasitology.

"Toxoplasma gondii is pretty remarkable…many people call it the most successful parasite on the planet because it can infect any nucleated cell in virtually any warm-blooded vertebrate…most parasites have a single host, maybe two hosts," he explains.

Among many topics, Dr. Sullivan explains what type of evidence suggests that Toxoplasma gondii is able to recognize what type of host cell it is in, how the active invasion process works, how long it takes before a host immune response is initiated by the presence of Toxoplasma gondii, how this parasite can affect host behavior and personality, how long the latent stages of the infection can last, and what's being done to address human health concerns posed by this parasite.

Check out www.sullivanlab.com for more information.