Isolation and Molecular Analysis of Negeviruses in Mosquitoes (Diptera: Culicidae) from an Environmental Protection Area in the Brazilian Amazon

Mosquitoes are recognized as the arthropod group with the greatest vectorial capacity, and the viruses they transmit constitute a significant concern in the context of global One Health. In addition, these insects act as hosts for a wide diversity of insect-specific viruses (ISVs), which exclusively infect arthropods. Expanding knowledge of ISVs is particularly relevant, given their potential influence on arbovirus replication and their role in elucidating the evolutionary processes that shape virus–vector interactions. In this study, we report the isolation and molecular analysis of three negeviruses associated with different mosquito species of the genera Culex, Coquillettidia, Mansonia, and Ochlerotatus, collected in Belém, Pará State, in the Brazilian Amazon: Loreto virus, Wallerfield virus, and a putative new species, designated Terra firme virus. Eleven pools exhibited cellular alterations consistent with cytopathic effects in invertebrate C6/36 cells but showed no evidence of replication in vertebrate Vero cells. Notably, simultaneous infections by two or three negeviruses were detected in some mosquito pools, indicating the occurrence of multiple viral infections within individual samples. Genomic analyses revealed that the isolated strains share conserved domains with previously described isolates from other countries. Phylogenetic inferences demonstrated that the investigated strains are classified within the clades Nelorpivirus and Sandewavirus. Taken together, these findings expand the currently known diversity of the negevirus group and contribute to a more comprehensive understanding of its host range and geographic distribution.