Methicillin-resistant Staphylococcus aureus (MRSA) mitral valve acute bacterial endocarditis (ABE) in a patient with job's syndrome (hyperimmunoglobulin E syndrome) successfully treated with linezolid and high-dose daptomycin

Job's syndrome (hyperimmunoglobulin E syndrome) is a congenitally acquired primary immune deficiency. The primary host defense defect in Job's syndrome is impaired phagocytosis. Accordingly, patients with Job's syndrome have difficulties eradicating staphylococcal infections. A continuous, high-grade Staphylococcus aureus bacteremia with a cardiac valve vegetation is the hallmark of S. aureus acute bacterial endocarditis (ABE). ABE may be caused by methicillin-sensitive Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA). We report a case of Job's syndrome MRSA mitral valve ABE. Presumably because of impaired phagocytic function, his MRSA ABE was complicated by extensive metastatic septic complications manifested as brain abscess, multiple epidural abscesses, and multifocal vertebral osteomyelitis. The patient did not respond to 5 days of appropriately dosed linezolid and daptomycin and remained bacteremic because abscess drainage was not an option in this case and the continuous, high-grade MRSA bacteremia continued despite appropriate therapy. High-dose daptomycin (12 mg/kg intravenously every 24 hours) was given, and his MRSA bacteremia was rapidly terminated. Because daptomycin does not cross the blood-brain barrier in therapeutic concentrations, linezolid was used to treat the brain abscess. The extensiveness of infection in this case is remarkable and is probably related to impaired phagocytic function from Job's syndrome. High-dose daptomycin therapy rapidly cleared the bacteremia and cured the endocarditis and epidural abscesses/vertebral osteomyelitis. The patient was treated with 8 weeks of high-dose daptomycin therapy with no adverse effects. If MRSA and methicillin-sensitive S. aureus bacteremias are unresponsive to usually effective antistaphylococcal agents, and surgical drainage of abscesses and removal of infected devices are not clinically possible, then a prolonged, high dose of daptomycin is a therapeutic alternative in such situations. To the best of our knowledge, this is the first case of MRSA mitral valve ABE complicated by extensive epidural abscesses and vertebral osteomyelitis in a patient with Job's syndrome.