Using Zebrafish to Observe How Meningitis Infects the Brain
05 Oct 2015

Researchers from Duke University watch in real time as Cyptoccoccal meningitis moves through tissue, blood vessels and into the brain of transparent zebrafish larvae.

There are a number of reasons scientists decided to use zebrafish to learn more about how the organism moves into the blood stream and through the blood-brain barrier. For one, zebrafish larvae have clear bodies, so they can watch the infection take hold.

“What’s impressive is that, unlike in a mouse or rabbit, you can actually see the organism producing disease in the live animal,” said John R. Perfect, M.D., chief of the division of infectious diseases at Duke University School of Medicine. “Day-by-day, it’s growing and moving throughout the body.  You can’t see this anywhere else.”

Using zebrafish also provides a small vertebrate animal that has a somewhat similar immune systems to humans.  The fish are easier to study than a mouse or larger animal, and since they are tiny they are easy to reproduce and cost less. Finally, small molecules can permeate the larvae, which will allow scientists to batch-test different drug compounds against the infection relatively quickly and easily, according to co-author David Tobin, Ph.D., assistant professor in Molecular genetics and microbiology and immunology at Duke.

One limitation of study is that zebra fish lack lungs, which is where Cryptococcus enters the human body.  Airborne cells of Cryptococcus usually do not affect healthy people, but those with weak immune systems, such as those with HIV infection or undergoing cancer treatment, a Cryptococcus meningitis infection can be fatal.