[SCAN] Staphylococcus epidermidis biofilm metabolism and matrix remodelling promotes resistance to nitrosative stress

Title: Staphylococcus epidermidis biofilm metabolism and matrix remodelling promotes resistance to nitrosative stress

Speaker: Sandra Carvalho

From: ITQB NOVA

Abstract: Staphylococcus epidermidis is a major pathogen in medical device-associated infections. Its pathogenicity derives from the ability to form adherent biofilms that evade the host immune system and are highly resistant to antibiotics. Macrophages are the first cells of the host innate immunity infiltrating the tissues where the biomaterials are implanted and bacterial clearance in the post-implantation phase of the medical device is crucial in the prevention of deleterious infections. Macrophages promote bacterial eradication mainly through activation of the eukaryotic inducible nitric oxide synthase (iNOS) that generates nitric oxide. Most research has focused on studying the responses to host-imposed stresses on planktonic bacteria, leaving a gap of knowledge on how bacteria thrive on toxic concentrations of nitric oxide (NO) produced by host innate immune cells during biofilm assembly. S. epidermidis is able to form biofilms in the presence of nitric oxide (NO.) and derived reactive nitrogen species (RNS), known to cause deleterious nitrosylation of several cellular life support enzymes. We have used 1H NMR, RT-qPCR and confocal microscopy to uncover how S. epidermidis survives NO stress while forming biofilms.