Toward Uncovering the Complexities of Bacterial Interspecies Communication and Competition on the Skin.

The skin is an inhospitable environment for microbial growth and survival. Hallmarks of the skin microenvironment include low moisture, high acidity, high lipid content, and paucity of essential nutrients, which together establish an antimicrobial barrier that defends against pathogens. Yet, commensal microbes and some opportunistic pathogens call this harsh environment home. The coagulase-negative staphylococci (CoNS) comprise a major constituent of the commensal skin microbiome. Of the CoNS, Staphylococcus epidermidis and Staphylococcus hominis are two common colonizers of human skin. Although comparatively less studied than S. epidermidis, there is a growing appreciation for S. hominis as a beneficial commensal, prompting interest in understanding the mechanisms by which S. hominis interacts with other skin microbes, including those with pathogenic potential. In their recent work, M. M. Severn, M. R. Williams, A. Shahbandi, Z. L. Bunch, et al. [mBio 13(3):e00930-22, 2022, https://doi.org/10.1128/mbio.00930-22] explore quorum sensing as a mediator of S. hominis interbacterial communication that can reduce the virulence of pathogens.