A Gram-positive three-component antimicrobial peptide-sensing system

To survive during colonization or infection of the human body, microorganisms must defeat antimicrobial peptides, which represent a key component of innate host defense in phagocytes and on epithelia. However, is not known how the clinically important group of Gram-positive bacteria sense antimicrobial peptides to coordinate a directed defensive response. By determining the genome-wide gene regulatory response to human beta defensin 3 in the nosocomial pathogen Staphylococcus epidermidis, we discovered an antimicrobial peptide sensor system that controls major specific resistance mechanisms to antimicrobial peptides and is unrelated to the Gram-negative PhoP/PhoQ system. Keywords: Wild type control vs treated vs mutant Wild type untreated in triplicate is compared to wild type treated in triplicate along with three mutants in triplicate with and without treatment of human beta defensin 3, totalling 30 samples