Which pathogens are most commonly associated with infective endocarditis?

The most commonly associated pathogens with infective endocarditis are indeed Streptococcus viridans and Staphylococcus aureus.

Streptococcus viridans is part of the normal flora of the mouth and is frequently involved in cases of dental procedures or poor dental hygiene, which can introduce bacteria into the bloodstream. Once in circulation, these bacteria can lodge in heart valves or endocardial surfaces, leading to infection.

Staphylococcus aureus, on the other hand, is often found on the skin and in nasal passages, and it is particularly virulent. This pathogen can cause endocarditis more acutely, particularly in patients with existing heart conditions or prosthetic heart valves, leading to significant morbidity and mortality.

Identifying these two organisms is critical for the diagnosis and treatment of infective endocarditis, as they dictate the choice of antibiotics and the urgency of intervention. Understanding their role in this condition emphasizes the importance of prophylaxis in susceptible patients, especially before procedures that may cause bacteremia.