Staphylococcus aureus is a bacterium commonly found on the skin and nares of both humans and animals. However, it can become an opportunistic pathogen, causing a variety of clinical manifestations, from minor skin infections to life-threatening diseases, including pneumonia, osteomyelitis and endocarditis. The treatment of S. aureus infections has become increasingly difficult due to the emergence of antibiotic-resistant strains in clinical context and the spreading of these strains in the community.
Nowadays, it is known that S. aureus can live inside host cells and this intracellular lifestyle is crucial for infection dissemination and persistence. Also, intracellular bacteria may be protected from the activity of antimicrobials, leading to treatment failure and post-therapy relapse. In order to successfully invade and survive inside host cells, S. aureus needs to modulate host cell functions through several mechanisms. MiRNAs are small molecules present in host cells, which are capable of regulating cellular gene expression and, thus, influence the outcome of S. aureus infection.
In this context, the goal of this study was to discover miRNAs that regulate S. aureus invasion, survival, and replication within host cells. The knowledge of these factors may potentially reveal novel therapeutical targets to control S. aureus infection.