Which microorganism is responsible for prosthetic valve endocarditis occurring within 60 days after surgery?

Explanation

Prosthetic valve endocarditis developing within 60 days post-surgery is most commonly caused by Staphylococcus epidermidis, a coagulase-negative staphylococcus known for its ability to form biofilms on prosthetic material. Other organisms such as Viridans streptococci, Staphylococcus aureus, and fungi are less frequently implicated in early prosthetic valve infections.