Constrictive Pericarditis from Methicillin-Sensitive <i>Staphylococcus </i><i>aureus</i>: A Case of Source and Seeding with Persistent Bacteremia

Staphylococcus aureus pericarditis is a rare but life-threatening condition that often presents as purulent pericarditis and in rare cases can lead to constrictive pathophysiology. Methicillin-sensitive Staphylococcus aureus (MSSA) as a cause of constrictive pericarditis is uncommon. A 65-year-old male with diabetes presented with chest pain and was diagnosed with pericarditis. Blood cultures confirmed MSSA bacteremia, and imaging revealed loculated pericardial effusion with features consistent with constrictive pericarditis. Pericardiocentesis revealed MSSA-positive serous fluid, and the patient underwent prolonged antimicrobial therapy. Despite initial clinical improvement, he developed recurrent MSSA bacteremia with vertebral osteomyelitis and an epidural abscess. He underwent surgical spinal debridement and stabilization, followed by extended intravenous antibiotic therapy. The patient’s symptoms ultimately resolved, and follow-up imaging showed significant improvement. This is an atypical presentation of constrictive pericarditis from community-acquired MSSA and this case demonstrates the diagnostic complexity of MSSA bacteremia and the importance of source control.