The iron-regulated small regulatory RNA IsrR modulates expression of genes utilized for dioxygen metabolism and heme synthesis in <i>Staphylococcus aureus</i>

<i>Staphylococcus aureus</i> causes numerous and varied infections in mammals, making it a significant public health burden and concern. The prevalence of <i>S. aureus</i> infections is due to its robust repertoire of virulence factors and its ability to adapt to host microenvironments. Elucidation of the metabolic processes and pathways that promote adaptation to host-promoted stressors provides information about host-pathogen interactions. It could also aid the development of new antimicrobials or unveil treatment and prevention strategies. One common stress bacteria encounter within the mammalian hosts is limited access to iron. In response to iron scarcity, <i>S. aureus</i> expresses the regulatory sRNA IsrR. Here, we identified mRNAs that associate with IsrR. We verified that IsrR targets mRNAs that code for proteins involved in aerobic respiration, the metabolism of reactive oxygen species, and heme synthesis. This work provides significant insight into how <i>S. aureus</i> responds to host-mediated iron starvation.