RESUMO
INTRODUCTION: Nanoparticles (NPs) have been widely studied as an alternative to antibiotic use due to their antimicrobial properties at lower concentrations. Enterococcus faecalis is a facultative Gram-positive microorganism inhabiting the gastrointestinal tract of humans and animals. It can also be present in other environments such as the oral cavity, water, sewage, soil and food. AIMS: We evaluated whether E. faecalis could develop resistance to silver NPs (AgNPs) after exposure to sublethal concentrations of the NPs. METHODS AND RESULTS: Proteomic analyses revealed that different pathways were activated during the acquired resistance under sublethal concentrations, and selected genes were validated by qPCR. CONCLUSIONS: The results of this study showed that E. faecalis is capable of generating resistance to AgNPs. SIGNIFICANCE AND IMPACT OF THE STUDY: To avoid the generation of resistance against AgNPs, future use of these NPs should be combined with other NPs prepared with different metals to prevent the dissemination of resistant strains.