The main goal of the project consisted on developing immunochemical technologies to build up fast and accurate diagnostic methods to detect S. aureus and P. aeruginosa and to profile the expression of different QS signaling molecules. For this, the generation of specific antibodies against important QS signaling molecules was carried out. Subsequently, immunochemical analytical tools for these selected QS molecules were developed, reaching the limits of detection needed to be able to quantify real samples. To assess the potential value of selected target QS molecules as biomarkers of infection, their profile in clinical samples obtained from patients suffering lower respiratory tract infections were analyzed.