Investigating Peptidoglycan Recycling Pathways in with -Acetylmuramic Acid Bioorthogonal Probes.

The human oral microbiome is the second largest microbial community in humans, harboring over 700 bacterial species, which aid in digestion and protect from growth of disease-causing pathogens. One such oral pathogen, along with other species, contributes to the pathogenesis of periodontitis. is unable to produce its own -acetylmuramic acid (NAM) sugar, essential for peptidoglycan biosynthesis and therefore must scavenge NAM from other species with which it cohabitates. Here, we explore the recycling potential of for NAM uptake with a bioorthogonal modification into its peptidoglycan, allowing for click-chemistry-based visualization of the cell wall structure. Additionally, we identified NAM recycling enzyme homologues in that are similar to the enzymes found in These homologues were then genetically transformed into a laboratory safe strain, resulting in the efficient incorporation of unnatural NAM analogues into the peptidoglycan backbone and its visualization, alone or in the presence of human macrophages. This strain will be useful in further studies to probe NAM recycling and peptidoglycan scavenging pathways of and other cohabiting bacteria.