Coagulase-Negative Staphylococcal Strain Prevents Staphylococcus aureus Colonization and Skin Infection by Blocking Quorum Sensing

Publication date: 13 December 2017
Source:Cell Host & Microbe, Volume 22, Issue 6
Author(s): Alexandra E. Paharik, Corey P. Parlet, Nadjali Chung, Daniel A. Todd, Emilio I. Rodriguez, Michael J. Van Dyke, Nadja B. Cech, Alexander R. Horswill
Coagulase-negative staphylococci (CoNS) and Staphylococcus aureus are part of the natural flora of humans and other mammals. We found that spent media from the CoNS species Staphylococcus caprae can inhibit agr-mediated quorum sensing by all classes of S. aureus. A biochemical assessment of the inhibitory activity suggested that the S. caprae autoinducing peptide (AIP) was responsible, and mass spectrometric analysis identified the S. caprae AIP as an eight-residue peptide (YSTCSYYF). Using a murine model of intradermal MRSA infection, the therapeutic efficacy of synthetic S. caprae AIP was evident by a dramatic reduction in both dermonecrotic injury and cutaneous bacterial burden relative to controls. Competition experiments between S. caprae and MRSA demonstrated a significant reduction in MRSA burden using murine models of both skin colonization and intradermal infection. Our findings indicate that important interactions occur between commensals that can impact disease outcomes and potentially shape the composition of the natural flora.

Graphical abstract

Teaser

Paharik, Parlet, et al. demonstrate that the human commensal Staphylococcus caprae competes with Staphylococcus aureus by inhibiting quorum sensing. Through signal interference, S. caprae reduces methicillin-resistant S. aureus burden in both skin colonization and infection, highlighting the benefits of healthy skin flora and suggesting a new avenue for probiotic therapy.


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