Adaptation Response Mechanisms of Staphylococcus epidermidis Strains Exposed to Increasing Concentrations of Didecyldimethylammonium Chloride

Transporters and Efflux Pumps Are the Main Mechanisms Involved in Staphylococcus epidermidis Adaptation and Tolerance to Didecyldimethylammonium Chloride

“…However, for SE11Ad, the reduced expression of genes involved in the Agr system was identified as the mechanism that might have a large contribution in adaptation to DDAC, as reduced expression of the genes of the Agr system enhance biofilm formation as a response to DDAC. Indeed, stronger biofilm formation was detected in SE11Re, in comparison to the control SE11 [19]. The Agr system also regulates some extracellular proteases, such as V8 protease (SE1543, -534.6-fold).…”

“…The DDAC minimal inhibitory concentration (MIC) against SE11Ad was 18.0 µg/mL, while for the control SE11 this was lower, at 4.5 µg/mL. The DDAC MIC against SE18To was 9.0 µg/mL, and against SE18 it was 0.6 µg/mL [19].…”

“…The S. epidermidis SE11 and S. epidermidis SE18 cleanroom strains were used as the control strains (henceforth referred to as SE11, SE18). These strains had been exposed to DDAC (Merck, Darmstadt, Germany) in our previous study [19]. The DDAC-adapted SE11Ad and DDAC-tolerant SE18To S. epidermidis strains obtained were used in the present study (henceforth referred to as SE11Ad, SE18To).…”

“…Here, tolerance remains even after the removal of the disinfectant, and it can be transferred across generations [16]. Several bacterial adaptation and tolerance mechanisms are known to be involved, such as modulation of cell growth rate, biofilm formation, efflux pump activity, fatty-acid profile, and the cell size, cell membranes and cell wall [16][17][18][19]. However, in general, tolerance development to QACs is still not fully understood [13].…”

“…In the present study, we used the adapted and tolerant S. epidermidis cleanroom strains that we had previously obtained by their exposure to sub-inhibitory concentrations of DDAC [19]. We aimed to gain insight into the transcriptomic changes for the biological processes involved in the adaptation and tolerance mechanisms of these S. epidermidis cleanroom strains.…”