Viral-bacterial co-infections screen reveals molecular processes affecting pathogen proliferation and host cell viability
In a new study published in Nature Communications, Philipp Walch from the Lab of Petr Broz, uncovers new mechanisms by which co-infections can worsen disease outcome. As it isw ell known, Infectious diseases pose a severe threat to public health and have recently moved back into the focus of both the scientific research community, as well as the broad public. A major risk factor in the clinical outcome of infectious diseases is the occurrence of secondary infections with another pathogen. Such co-infections occur often in the intestinal tract as well as in the lung, where co-infections with Influenza virus and staphylococcus or streptococcus bacteria increase disease severity and fatality and are commonly isolated from hospitalized patients. To better understand the crosstalk between viruses and bacteria during infections, we carried out a pair-wise infection screen using either murine Adenovirus (mAdV) or murine Norovirus (MNV) in combination with a panel of enteropathogenic bacteria, spanning Salmonella, Shigella, Citrobacter, Vibrio, Yersinia and Escherichia, using host cell death and pathogen growth or clearance as initial metrics. This screen highlights several examples of how co-infections can worsen disease outcomes for the host: For example, we find that infections with mAdV reprograms the host cell in a way that favors Yersinia invasion of the cells. Another example shows that infections with mAdV also suppress the induction of host cell death thus impacting the secondary infection with Salmonella. Thus, our study provides new mechanistic insights explaining why co-infections can result in a worsened outcome, and thus could pave the way for new therapeutic strategies.