Staphylococus aureus is one of the most prevalent bacteria in health-care system among the pathogens found in lower respiratory tract infections (LRTIs), which additionally has an increasing impact due to their methicillin resistance activity (MRSA). The basis of our technology is built over the knowledge about how the bacteria is communicating each other (Quorum sensing, QS). Specifically, QS in S. aureus is mediated by autoinducer peptides (AIPs) that control the agr system responsible for the expression of the virulence factors, growth and biofilm formation. Thus, the detection of certain levels of AIPs is a clear indication that an infection is present in the lower respiratory tract. We have produced antibodies against four different AIPs that can be present in a S. aureus infection and we have developed four different ELISA assays for their detection.

The project aimed to add value to the technology developed and demonstrated its feasibility and reliability to detect AIPs in LRTIs. Analytical chacterization and clinical validation was proposed to valorize the technology. Initial studies and characterization of those antibodies revealed a high detectability (in the µg/L range) in buffer and culture media. The main investigations performed in the Phisaureus project pursued to implement in bronchoalveolar aspirates as a matrix of interest.