A giant virus infecting the amoeboflagellate Naegleria

Patrick Arthofer, Florian Panhölzl, Vincent Delafont, Alban Hay, Siegfried Reipert, Norbert Cyran, Stefanie Wienkoop, Anouk Willemsen, Ines Sifaoui, Iñigo Arberas-Jiménez, Frederik Schulz, Jacob Lorenzo-Morales, Matthias Horn (Corresponding author)

Publications: Contribution to journalArticlePeer Reviewed


Giant viruses (Nucleocytoviricota) are significant lethality agents of various eukaryotic hosts. Although metagenomics indicates their ubiquitous distribution, available giant virus isolates are restricted to a very small number of protist and algal hosts. Here we report on the first viral isolate that replicates in the amoeboflagellate Naegleria. This genus comprises the notorious human pathogen Naegleria fowleri, the causative agent of the rare but fatal primary amoebic meningoencephalitis. We have elucidated the structure and infection cycle of this giant virus, Catovirus naegleriensis (a.k.a. Naegleriavirus, NiV), and show its unique adaptations to its Naegleria host using fluorescence in situ hybridization, electron microscopy, genomics, and proteomics. Naegleriavirus is only the fourth isolate of the highly diverse subfamily Klosneuvirinae, and like its relatives the NiV genome contains a large number of translation genes, but lacks transfer RNAs (tRNAs). NiV has acquired genes from its Naegleria host, which code for heat shock proteins and apoptosis inhibiting factors, presumably for host interactions. Notably, NiV infection was lethal to all Naegleria species tested, including the human pathogen N. fowleri. This study expands our experimental framework for investigating giant viruses and may help to better understand the basic biology of the human pathogen N. fowleri.

Original languageEnglish
Article number3307
Number of pages13
JournalNature Communications
Issue number1
Early online date24 Apr 2024
Publication statusE-pub ahead of print - 24 Apr 2024

Austrian Fields of Science 2012

  • 106026 Ecosystem research
  • 106022 Microbiology


  • parasitic infection
  • virology

Cite this