Researchers at the University of Vienna have discovered giant viruses that infect the deadly parasite Naegleria fowleri. This parasite, found in warm waters, causes a rare but fatal brain infection known as primary amoebic meningoencephalitis. The team, led by Matthias Horn and Patrick Arthofer, isolated these viruses from a waste water treatment plant in Austria. The viruses, named Naegleriavirus, belong to the group of giant viruses known as Nucleocytoviricota.
Giant viruses were only identified two decades ago and are known for their unusually large size and complex genomes. They infect single-celled organisms and possess unique structures and genetic traits that were previously thought to be exclusive to cellular life. The discovery of Naegleriaviruses has expanded our understanding of these giant viruses and their interactions with their amoeba hosts. Naegleriaviruses are taken up by amoebae as a food source but quickly destroy their hosts within hours, forming viral factories that replicate genetic material and produce new virus particles.
The team’s research was conducted in collaboration with international researchers from universities in Poitiers, the Canary Islands, and the US-based Joint Genome Institute. The Naegleriaviruses are only the fourth isolate from a group known as Klosneuviruses, which are a subset of giant viruses. These viruses infect host cells through a stargate structure that allows for DNA entry and use special proteins to suppress the host cell’s immune response, prolonging the cell’s survival to facilitate viral replication before cell destruction and virus release.
Although the Naegleriaviruses may not be suitable for treating Naegleria infections in the brain due to accessibility challenges, they could potentially be used for preventative treatment in water bodies at risk for contamination. This discovery opens the door to further research on using viruses to combat waterborne pathogens, such as in swimming pool water treatment. By enhancing our understanding of Naegleria biology and the viruses that infect them, this research contributes to our knowledge of both the parasite and potential treatment options.
The discovery of Naegleriaviruses sheds light on the interactions between giant viruses and their amoeba hosts and provides insight into the complex biology of these deadly parasites. The team’s findings, published in Nature Communications, highlight the potential for using viruses in preventative treatments for waterborne pathogens and expand our knowledge of the diverse world of viruses that infect single-celled organisms. Further research in this area may lead to new ways to combat harmful parasites and prevent fatal infections, ultimately improving public health and safety.
