# A Marseillevirus isolate from the Brazilian wetlands

## TL;DR

A new giant virus, Marseillevirus pantanense, was isolated from the Brazilian Pantanal and characterized for its genome and structure.

## Contribution

The discovery and characterization of a new Marseillevirus strain from the Brazilian Pantanal wetlands.

## Key findings

- Marseillevirus pantanense has icosahedral particles approximately 190 nm in diameter.
- The virus has a 379,900-bp genome with 496 open reading frames, including 12 ORFans and two tRNAs.
- Phylogenetic analysis places M. pantanense within Marseillevirus lineage A, group I.

## Abstract

Marseilleviruses are giant viruses that infect amoebas and have been isolated from various environments. Here, we describe a new strain, isolated from a water sample collected from the Paraguay River in the Brazilian Pantanal, which we have named "Marseillevirus pantanense". Transmission and scanning electron microscopy revealed icosahedral particles approximately 190 nm in diameter. Genomic and phylogenetic analyses show that M. pantanense has a 379,900-bp genome with 496 open reading frames, including 12 ORFans and two tRNAs. Furthermore, phylogenetic analysis places M. pantanense within Marseillevirus lineage A, group I. The findings of in this study underscore the importance of isolating new viruses to expand our understanding of the abundance and distribution of giant viruses in Brazilian biomes.

The online version contains supplementary material available at 10.1007/s00705-025-06456-6.