**4.8. Methicillin-susceptible** *Staphylococcus aureus* **(MSSA) and methicillin-resistant** *Staphylococcus aureus* **(MRSA) infection**

*Staphylococcus aureus* represents the primary pathogen in IE in HD patients causing up to 80% of the IE. This pathogen is much more frequent than in the general population with IE. This can be explained that more than 50% of patients in dialysis are carriers of *S. aureus*; nose as a reservoir has shown an increased risk of subsequent infections. It is also important to consider that this pathogen by the fact is responsible for a high number of septic complications compared with other microorganisms. Finally, recent studies have shown that as much as 50% of *S. aureus* IE is MRSA. These strains in particular are more difficult to eradicate and are associated with a worse prognosis than methicillin-susceptible *S. aureus*. In general, patients with MRSA got it as an in-hospital infection; however, studies have shown the existence of community-acquired strains, which are microbiologically different from those acquired during hospitalization. Those strains are called community-acquired *Staphylococcus aureus* methicillinresistant (CA-MRSA). It is a predisposing factor in these patients and a challenge for physicians involved with patients with MRSA IE [1, 5, 24].
