How do fluorescence spectroscopy and multimodal fluorescence imaging help to dissect the enhanced efficiency of vancomycin-rifampin combination against Staphylococcus aureus infections?
Résumé
Staphylococcus aureus is one of the most frequent pathogens responsible for biofilm-associated infections. Among current clinical antibiotics, very few enable long-term successful treatment. Thus, it becomes necessary to better understand antibiotics failures and successes in treating infections in order to master the use of proper antibiotic therapies. In this context, we took benefit from a set of fluorescence spectroscopic and imaging methods, with the support of conventional microbiological tools to better understand the vancomycin-rifampin combination (in)efficiency against S. aureus biofilms. It was shown that both antibiotics interacted by forming a complex. This latter allowed a fastened penetration of the drugs before dissociating from each other to interact with their respective biological targets. However, sufficiently high concentrations of free vancomycin should be maintained, either by increasing vancomycin concentration or by applying repetitive doses of the two drugs, in order to eradicate rifampin-resistant mutants.