“…We present a case in which an elderly immunocompromised patient developed meningitis due to a combination of S. mitis and N. subflava, both of which are natural inhabitants of the mucous membranes of the upper respiratory tract and are generally considered to be benign bacteria [ 1 , 2 , 3 , 4 , 5 ]. Meningitis has been reported to be caused by S. mitis or N. subflava alone in cases involving spinal anesthesia, neurosurgical procedures, malignancy, neurological complications of endocarditis, or in newborns [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Older age, the use of immunosuppressants, DM, and dental treatment played important roles in the present case, in which the patient was treated with ceftriaxone because it diffuses more readily into the CSF than other drugs.…”