Discovery and pathology of novel viruses associated with the unexplored model, Hermetia Illucens (Black Soldier Fly)

• Autores: Robert Daniel Pienaar
• Directores de la Tesis: Elisabeth Herniou (dir. tes.), Salvador Herrero Sendra (codir. tes.)
• Lectura: En la Universitat de València ( España ) en 2024
• Idioma: español
• Tribunal Calificador de la Tesis: Antoine Touzé (presid.), Nolwenn Dheilly (secret.), Jonathan Filée (voc.), Vera Ingrid Ros (voc.), Morena Casartelli (voc.)
• Programa de doctorado: Programa de Doctorado en Biomedicina y Biotecnología por la Universitat de València (Estudi General)
• Materias:
  • Ciencias económicas
    • Economía sectorial
      • Sanidad
• Enlaces
  • Tesis en acceso abierto en: webges.uv.es (pdf)
• Resumen

  • This thesis investigated the virome of black soldier flies (BSF, Hermetia illucens), a key species in the insect mass-rearing industry. Prior to this study, there was limited knowledge about viruses infecting BSFs. Initially, we searched for endogenized viral elements in BSF genomes, discovering nine DNA regions of viral origin related to five insect-infecting virus families: Partitiviridae, Parvoviridae, Rhabdoviridae, Lebotiviridae (formerly Totiviridae), and Xinmoviridae. We then examined BSF metatranscriptomic and metagenomic datasets, identifying six exogenous viruses from six families: Discistroviridae, Iflaviridae, Inseviridae, Lebotiviridae, Rhabdoviridae, and Solinviviridae. This led to the development of bioinformatic and molecular tools for high-throughput virus screening, revealing widespread viral presence in BSF colonies globally, including industrial farms and academic labs. Some colonies were simultaneously infected with multiple viruses. To assess pathogenicity, we isolated Hermetia illucens solinvivirus (HiSvV) and conducted bioassays. We found that HiSvV-infected BSF adults died significantly sooner than non-infected ones, confirming HiSvV's pathogenicity. Experiments showed HiSvV transmission between BSFs and infection via oral and subcutaneous routes. Further, we studied immune gene responses in BSFs during HiSvV infection and in populations with natural co-infections of Hermetia illucens sigmavirus (HiSgV) and Hermetia illucens insevirus (HiInV). This thesis demonstrates that BSFs host diverse viruses and have done so for a long time. This work provides new tools and cost-effective methods for detecting known viruses in BSF colonies, highlighting the need for inclusive BSF welfare practices in rearing facilities to manage and prevent viral infections.