Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Meningitis model shows infection's sci-fi-worthy creep into the brain

29.09.2015

Scientists at Duke Medicine are using transparent fish to watch in real time as Cryptococcal meningitis takes over the brain. The resulting images are worthy of a sci-fi movie teaser, but could be valuable in disrupting the real, crippling brain infection that kills more than 600,000 people worldwide each year.

Airborne cells of Cryptococcus make their way into our lungs practically every day -- unwelcome guests, but of little consequence for those with healthy immune systems. But for those with compromised immunities, whether by HIV infection or cancer treatment, a resulting Cryptococcal meningitis infection can quickly become deadly.


A zebrafish larva is infected with Cryptococcal meningitis and photographed under a microscope. Scientists observe as the infection (visible red orbs) takes over the brain. Macrophages (shown in blue) attack the infection as it travels through green blood vessels and throughout surrounding tissue. The eyes of the fish are located at the top- and bottom-left corners of the image.

Credit: Stefan Oehlers/Duke Medicine

To be able to target the infection with medications in the future, researchers need to know more about how the organism (technically a yeast), moves from the lungs into the blood stream and through the blood-brain barrier. So they injected the organism into microscopic zebrafish larvae, which have clear bodies, and watched the infection take hold.

The newly developed fish model is described in mBio, a journal of the American Society of Microbiology

"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."

A video shows a transparent larva's body as Cryptococcus fungi, made red by a fluorescent tracer, moves through tissue, blood vessels and into the brain. Blue macrophages chase and gobble up some of the red infection as it spreads through and around green blood vessels.

Using a zebrafish to observe the process of infection offers a small vertebrate animal with an immune system somewhat similar to a human's, Perfect said. Because the fish are tiny and easy to reproduce, they cost less and are easier to study than a mouse or larger mammal.

The larvae are also permeable to small molecules, which will allow scientists to batch-test different drug compounds against the infection relatively quickly and easily, said co-author David Tobin, Ph.D., assistant professor in molecular genetics and microbiology and immunology at Duke.

"This model will allow researchers to screen the whole organism while it is living with an infection," Tobin said. "It will allow us to screen libraries of drug compounds relatively quickly. We can also develop and test mutant strains of Cryptococcus in these larvae. This can teach us which factors play a role in infection and those could be therapeutic targets in the future."

Tobin also uses zebrafish to study bacteria closely related to those that cause tuberculosis, and findings from this model have been applied to understanding human disease.

There are some drawbacks to studying these infections in fish -- their body temperatures are cooler and they lack lungs, which is where Cryptococcus enters the human body, Perfect said. But the fish offer a starting point to create leads that scientists can then investigate further in more complex mammals.

"Our hope is that by creating this system, we can continue our own investigations into other harmful organisms, and that other scientists worldwide can adapt our zebrafish model to investigate the diseases that are priorities in their communities," Perfect said.

###

In addition to Perfect and Tobin, study authors include Jennifer L. Tenor; Stefan H. Oehlers; and Jialu L. Yang.

The study was sponsored by the Duke University Center for AIDS Research (CFAR), the National Institutes of Health (5P30 AI064518; 1DP2-OD008614; AI73896; AI93257), the Australian National Health and Medical Research Council, a Mallinckrodt Scholar Award, a Searle Scholar Award, the Vallee Foundation, and a Medicine Research Collaboration Award.

Media Contact

Samiha Khanna
samiha.khanna@duke.edu
919-419-5069

 @Duke_Medicine

http://www.dukemednews.org 

Samiha Khanna | EurekAlert!

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>