Projektdaten

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Phänotypische und genotypische Charakterisierung von Biofilm-assoziierten kleinen Kolonievarianten (SCV) von Enterokokken

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Biofilm-associated infections pose a significant challenge due to their tolerance to antibiotics and the immune response. This project focuses on the phenotypic and genotypic characterization of small colony variants (SCVs) of enterococci, a less explored area in the context of biofilm-associated infections. SCVs, characterized by slow growth and distinct morphological changes, are known to facilitate chronic infections by evading antibiotic effects. While extensively studied in Staphylococcus aureus, the molecular mechanisms leading to SCV formation in other Gram-positive bacteria, particularly enterococci, remain unknown. Despite clinical reports associating enterococcal small colony variants (SCVs) with relapses in infective endocarditis, existing diagnostic and therapeutic guidelines do not sufficiently address this phenomenon. Our previous in vitro biofilm studies indicated the selection of Enterococcus faecalis SCVs upon ?-lactam combination therapy. The project aims to comprehensively characterize these E. faecalis SCVs. The work plan includes ?-lactam antibiotic combination testing on E. faecalis biofilms, followed by the isolation and characterization of SCVs. Morphological and metabolic assessments will provide insights into the heterogeneity of SCV phenotypes, while virulence testing in Galleria mellonella larvae aims to elucidate potential differences in the virulence profiles of SCV phenotypes compared to normal colonies. Whole-genome sequencing will identify genetic biomarkers associated with SCV formation, contributing to a deeper understanding of the mechanisms driving biofilm-associated antibiotic tolerance in enterococci. This research not only addresses a critical gap in understanding enterococcal SCVs but also holds implications for the development of diagnostic and therapeutic strategies to combat biofilm-associated infections effectively.