In which population is Staphylococcus aureus commonly responsible for acute endocarditis?

Staphylococcus aureus is a significant cause of acute endocarditis, particularly in certain populations that are more susceptible to this condition. In adults over the age of 50, this pathogenic bacterium is particularly noteworthy because individuals in this age group may present with other co-morbid conditions that increase their risk of heart valve infections. Furthermore, they might have healthcare-associated risks or invasive procedures that can predispose them to this type of infection.

When considering pediatrics, Staphylococcus aureus can also lead to acute endocarditis, especially in children with underlying heart conditions or congenital defects. In this population, the presence of invasive devices or procedures can heighten the risk of infection from Staphylococcus aureus.

Given that both adults over 50 and pediatric patients are at risk for acute endocarditis due to Staphylococcus aureus, the most accurate description includes both populations, hence making the combined option the most comprehensive and correct answer. This reflects the broad epidemiological impact of Staphylococcus aureus on a diverse age demographic.