Daptomycin cure after cefazolin treatment failure of methicillin-sensitive Staphylococcus aureus (MSSA) tricuspid valve acute bacterial endocarditis from a peripherally inserted central catheter (PICC) line

Right-sided acute bacterial endocarditis (ABE) is an infrequent complication of central intravenous (IV) lines. We report a case of methicillin-sensitive Staphylococcus aureus tricuspid valve (TV) ABE related to a peripherally inserted central catheter line (PICC). Patients with right-sided ABE present with symptoms of fever and chills, and symptoms and signs of pulmonary emboli. In the patient presented, the PICC line was removed and high-dose cefazolin therapy, 2 g (IV) every 8 hours, was initiated. Although the patient's blood cultures became negative during the third week of cefazolin therapy, her erythrocyte sedimentation rate and teichoic acid antibody titers remained high. Pulmonary emboli developed. A large TV vegetation (1 x 2 cm) remained unchanged after 4 weeks of cefazolin therapy. For these reasons, cefazolin treatment was considered a treatment failure. Therapy with daptomycin was initiated at a dose of 6 mg/kg (IV) every 24 hours. During daptomycin therapy, the patient's erythrocyte sedimentation rate and teichoic acid antibody titers gradually returned to normal. Repeat transthoracic echocardiograph revealed the TV vegetation was gone and the methicillin-sensitive Staphylococcus aureus ABE was cured with daptomycin. We conclude daptomycin is a rapidly bactericidal antistaphylococcal antibiotic reliably effective even when other usually effective antistaphylococcal antibiotics have failed.