Infective endocarditis (IE) remains a major limitation of prosthetic materials in congenital heart disease (CHD), particularly after repeated interventions. Staphylococcus aureus is associated with severe outcomes, driven by its ability to form biofilms on implanted devices. However, the interaction between patient characteristics, bacterial phenotype and specific cardiac biomaterials remains poorly defined, limiting risk stratification and preventive strategies.

To identify bacterial and material determinants of IE by characterizing Staphylococcus aureus biofilm capacity and adhesion across biomaterials used in CHD, with the aim of informing clinical decision-making.

This pilot study part of a PhD program will include 50 S .  aureus strains isolated from patients with prosthetic IE (with and without CHD), compared with 20 reference strains. Three complementary analyses will be performed: (1) quantitative assessment of biofilm formation, (2) whole-genome analysis to identify virulence and biofilm-associated genes, (3) evaluation of bacterial adhesion and biofilm formation on clinically used materials, including valved conduits, homograft, pericardial tissue, valves and metallic platforms.

We expect to identify high-risk bacterial profiles associated with enhanced biofilm formation and preferential adhesion to specific biomaterials. Differences in colonization between materials may also explain the heterogeneous risk of IE observed in clinical practice.

This study targets a key unmet need in CHD: understanding why some patients and materials are more prone to IE. By linking bacterial phenotype to biomaterial susceptibility, the results may support: improved selection of valve type and material in high-risk patients, identification of patients requiring reinforced preventive strategies, development of targeted antimicrobial or anti-biofilm approaches.

This translational approach aims to move from empirical prevention toward personalized IE risk management in CHD.