With the increasing importance of insect as alternate protein source in the food and feed sector, manufacturers are increasingly confronted with the challenge of maintaining a healthy insect population. In order to ensure the health of the insects, constant monitoring of the presence of insect pathogens is often necessary in order to anticipate massive outbreaks and the associated collapse of the insect population. Here, we developed a diagnostic tool based on Oxford Nanopore Technologies’ MinION sequencer to rapidly screen for pathogens in insects. By implementing shotgun metagenomic sequencing techniques, no prior knowledge of the disease symptoms is required. The whole bioinformatics pipeline was integrated into an Nvidia Jetson AGX Xavier as a portable analytic tool. Notably, the entire process from the extraction of nucleic acids to the confirmation of the presence of viral sequences were completed within 24 hours.
Currently, at the research group of CBP – BIOTECHNOLOGICAL CONTROL OF PESTS (uv.es) in the University of Valencia, we are assessing the diagnostic tool for pathogen identification in an insect of economic and ecological relevance, Apis mellifera. Diseased honey bees were collected from the wild and will be examined using the newly developed diagnostic tool and validated by quantitative PCR. We will also be evaluating the tool for pathogen identification in Tenebrio molitor L., an economically important insect that was recently deemed safe for human consumption by the EU Food Safety Agency (EFSA).
We have also tested the tool on other insect models like the silkworm (Bombyx mori), cricket (Acheta domesticus) and codling moth (Cydia pomonella), and were able to detect the presence of pathogens in the colonies. Altogether, these findings demonstrated the potential of the developed sequencing and analytical tools to assist in timely diagnosis of infections in insects. Last month, our work was presented at the 2021 International Congress on Invertebrate Pathology and Microbial Control (SIP2021). We received great interests from the community and valuable feedback on how to further improve the system.