S. aureus REF: Nelson 17th edition page 863, "Meningitis due to S. aureus is not common; it is associated with cranial trauma and neurosurgical procedures ( e.g. craniotomy, cerebrospinal fluid shunt placement) and less frequently with endocarditis, parameningeal foci (e.g., epidural or brain abscess), diabetes mellitus, or malignancy. The CSF profile in S. aureus meningitis is indistinguishable from that in other bacterial causes of meningitis" Causes of bacterial meningitis vary by age group and comorbid conditions: Age Group & conditions Causes Premature babies & New- horns up to 3 month Group B Streptococci (mc), Streptococcus pneumoniae, Escherichia coli (carrying K1 antigen), Listeria monocytogenes Infants Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae Children (2-29 years) N. meningitidis (mc), S. pneumoniae Adult S. pneumoniae (mc), N. meningitidis, Mycobacteria Impaired cellular immunity L monocytogenes, gram-negative bacilli, S pneumoniae Postsurgical or posttraumatic Staphylococcus aureus, S pneumoniae, gram-negative bacilli