Bacterial meningitis due to the Streptococcus mitis group in children with cerebrospinal fluid leak.

The Streptococcus mitis group constitutes a part of the oral flora in humans and has been reported to cause infective endocarditis, brain abscesses, sepsis, pneumonia, and peritonitis. However, the S. mitis group rarely causes meningitis in children. We experienced a case of bacterial meningitis due to the S. mitis group in a 14-year-old girl with Gorham-Stout disease undergoing treatment with sirolimus for skull base osteolysis and cerebrospinal fluid (CSF) leak. Antibiotic treatment was initiated with linezolid and levofloxacin due to allergies against β-lactam antibiotics. On the third treatment day, antibiotics were switched to penicillin G according to CSF culture results, which were positive for penicillin-susceptible S. mitis group. Antibiotic therapy was successfully completed after 14 days without any neurological sequelae. There have apparently been no reports of S. mitis meningitis in pediatric patients with skull base osteolysis and CSF leak as in our case. Our findings suggest that clinicians should be aware of the possibility of S. mitis meningitis for patients with skull base osteolysis and/or CSF leakage.