Astrovirus and the microbiome

Abstract

Although astroviruses are most commonly associated with acute gastrointestinal illness in humans, their ability to infect a broad range of hosts and cause a spectrum of disease makes them widespread and complex pathogens. The precise mechanisms that dictate the course of astrovirus disease have not been studied extensively but are likely driven by multifactorial host-microbe interactions. Recent insights from studies of animal astrovirus infections have revealed both beneficial and detrimental effects for the host. However, further in-depth studies are needed to fully explore the consequences of astrovirus-induced changes in the gut microenvironment as well as the role of the microbiota in astrovirus infection.

Figure 1.. Changes in the diversity and composition of the microbiome after murine astrovirus infection.

Groups of 4 or 5 mice were orally gavaged with mock (PBS) or murine astrovirus (strain SJ002) inoculum. Fresh fecal pellets were collected at the time points indicated, and DNA was extracted for 16S rRNA gene (V3-V4) amplicon sequencing. Paired-end reads were merged and quality filtered using DADA2. A) Simpson’s Diversity Indices were calculated for the mock-infected and astrovirus-infected groups and compared. B) The relative frequencies of the operational taxonomic units are listed and shown as a color map according to genus.

Figure 2.. Astroviruses can induce both beneficial and detrimental effects on the gut microenvironment.

Avian astroviruses have been associated with the poultry enteritis mortality syndrome, which is characterized by outgrowth of atypical E. coli. In contrast, murine astrovirus infection can protect germ-free mice against other enteric virus pathogens independently of the microbiome.