Host-shift as the cause of emerging infectious diseases: Experimental approaches using Drosophila-virus interactions

Abstract

Host shifts, when a cross-species transmission of a pathogen can lead to successful infections, are the main cause of emerging infectious diseases, such as COVID-19. A complex challenge faced by the scientific community is to address the factors that determine whether the cross-species transmissions will result in spillover or sustained onwards infections. Here we review recent literature and present a perspective on current approaches we are using to understand the mechanisms underlying host shifts. We highlight the usefulness of the interactions between Drosophila species and viruses as an ideal study model. Additionally, we discuss how cross-infection experiments-when pathogens from a natural reservoir are intentionally injected in novel host species-can test the effect cross-species transmissions may have on the fitness of virus and host, and how the host phylogeny may influence this response. We also discuss experiments evaluating how cooccurrence with other viruses or the presence of the endosymbiont bacteria Wolbachia may affect the performance of new viruses in a novel host. Finally, we discuss the need of surveys of virus diversity in natural populations using next-generation sequencing technologies. In the long term, these approaches can contribute to a better understanding of the basic biology of host shifts.

Multiple long-range host shifts of major Wolbachia supergroups infecting arthropods

“…Wolbachia HS is a known event described by a wide range of literature 4 , 6 , 7 , 14 , 15 , 32 , 33 , yet it is still somewhat overlooked and sometimes disbelieved as a more common mechanism 19 , 20 , 30 , as it is still not very clear how it is established in some cases 13 . Nonetheless, Wolbachia has an arsenal of well described methods to thrive when first encountering a new host, which may explain its success jumping across clades by HS 6 .…”

Wolbachia infection in native populations of Blattella germanica and Periplaneta americana

“…In this study we found F supergroup in the cockroaches which is also found in distantly related host species including nematodes and domestic indoor pests ( Cimex , Supella and Blattella ). Wolbachia is transmitted either vertically between host generations or horizontally to other individuals and species through a mechanism called host shift (HS) [ 63 – 65 ].…”

The Antiviral Effects of the Symbiont Bacteria Wolbachia in Insects

“…One interesting interplay is that different Drosophila clades respond differently to viral infections (77), therefore, variation in resistance and susceptibility of hosts could be mirrored by the success and establishment of Wolbachia in some clades but not others in nature (78). In addition, it would be remarkably interesting to investigate how the presence of Wolbachia in some clades may affect the evolution of host-shifts by viruses (79).…”