Changes in the protein profiles of planktonic cultures and biofilms of <I>Staphylococcus epidermidis</I> under anaerobic conditions in the presence of the hormone CNP

Natriuretic peptides (NP) are able to affect biofilms of human commensal microorganisms, including representatives of the genus Staphylococcus, however, the literature lacks data on the molecular changes caused by these hormones at the posttranslational level. In this regard, the present work shows for the first time that C-type natriuretic peptide (CNP) induces large changes in protein profiles of Staphylococcus aureus cells and biofilms. The presence of the hormone leads to a more pronounced difference in protein profiles between planktonic cells and biofilms when compared to control pairs of samples. The main processes affected are TCA cycle, protein transport, purine synthesis (decrease in the amount of the corresponding proteins in biofilms) and nitrate metabolism (increase in the amount of nitrogenases and other proteins in biofilms). It is necessary to mention separately the decreased amount of lysostaphin in biofilms compared to planktonic cultures when exposed to CNP. This may be one of the potential mechanisms of the recently shown reduction of competitive properties of S. epidermidis in the community with other microorganisms, which is induced by the presence of CNP in the medium. In addition, the results of the study strengthen the hypothesis that, as in the case of other human hormones, the action of CNP on S. epidermidis , is multitargeted. One of the likely mechanisms of the hormone’s action may be the disruption of the transition from planktonic culture to biofilm, which can be assumed without suppressing cell growth, which needs further verification.