Gold Nanoclusters for Targeting Methicillin-Resistant Staphylococcus aureus In Vivo

Abstract

Widespread multidrug resistance caused by the abuse of antibiotics calls for novel strategies and materials. Gold nanoclusters (AuNCs) are scarcely explored for combating multidrug-resistant (MDR) bacteria in vivo. We herein synthesized a novel class of AuNCs, namely quaternary ammonium (QA) capped AuNCs (QA-AuNCs) as potent antibiotics selectively targeting MDR Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE), in vivo. QA-AuNCs kill bacteria through a combined physicochemical mechanism, and show excellent therapeutic effects in both a skin infection model and a bacteremia model induced by MRSA. In addition, owing to their intense fluorescence, QA-AuNCs can be used for the discrimination of live/dead bacteria and bacteria counting, suggesting their potential for clinical theranostics.

Keywords: Gram-positive bacteria; ammonium salts; antibiotics; drug resistance; gold nanoclusters.