Gut microbes play an important role in protecting the host against harmful bacteria, such as Enterrococcus faecium; however, antibiotics can deplete these microbes. In an effort to increase resistance to infections, a recent Science Translational Medicine report presents new evidence that murine noroviruses can actually prevent E. faecium infections in antibiotic-treated mice.
How can this virus prevent infection?
When inoculations of the norovirus were delivered to antibiotic-treated mice, increased expression of TLR7 was observed – a protein involved in antiviral and antibacterial immunity. Activation of TLR7 led to increased synthesis of antimicrobial peptides, which accelerated depletion of E. faecium colonies in the gut. The authors also demonstrated that the norovirus mimic, Resiquimod (R848) could be used to deplete these harmful bacteria by inducing expression of IL-22 and IL-23. Ultimately the results of this study present a potentially new target to stimulate the immune system when antibiotics are needed.
|Abt et al. TLR-7 activation enhances IL-22–mediated colonization resistance against vancomycin-resistant enterococcus.
Science Translational Medicine. 2016; 8(327): 327. DOI: 10.1126/scitranslmed.aad6663