How NAD+ Recycling Pathways Influence Virulence in Pneumonia Bacteria: Preclinical Findings

Synopsis

NAD is an essential molecule found in all living cells. Some bacteria, like Streptococcus pneumoniae, cannot make NAD from scratch and must recycle it by importing related compounds such as niacin or nicotinamide riboside using transporter proteins called NiaX and PnuC. This study examined how NiaX and PnuC function in S. pneumoniae strain TIGR4 and their role in the bacteria's ability to cause disease. It was found that NiaX specifically imports nicotinamide and nicotinic acid, while PnuC mainly imports nicotinamide riboside. Importantly, bacteria lacking PnuC were unable to cause infection in mouse models. These results highlight the critical role of NAD precursor import in S. pneumoniae virulence and suggest that PnuC could be a promising target for new treatments to prevent or reduce infection.

Journal

Microbiology