The reactions catalyzed by XO family enzymes are relevant during infection as potential substrate molecules occur in the host, and XO family enzymes are found in human pathogens, including several opportunistic pathogens and species on the WHO top priority pathogen list such as Acinetobacter baumannii, Mtb, and Enterobacteriaceae family species (World Health Organization, 2017). Here, XDH is linked to infection.