Population	Likely pathogen	Empiric therapy
Infants younger than 1 month	Streptococcus agalactiae (group B streptococcus), Listeria monocytogenes, Escherichia coli, other gram-negative bacilli	Ampicillin plus cefotaxime (Claforan)
		Alternative: ampicillin plus gentamicin
Children 1 to 23 months of age	Streptococcus pneumoniae, Neisseria meningitidis, S. agalactiae, Haemophilus influenzae, E. coli	Vancomycin plus ceftriaxone
		Alternative: meropenem (Merrem IV) plus vancomycin
Children and adults 2 to 50 years of age	N. meningitidis, S. pneumoniae	Vancomycin plus ceftriaxone
		Alternative: meropenem plus vancomycin
Adults older than 50 years or with altered cellular immunity or alcoholism	S. pneumoniae, N. meningitidis, L. monocytogenes, aerobic gram-negative bacilli	Vancomycin plus ceftriaxone plus ampicillin
		Alternative: meropenem plus vancomycin
Patients with basilar skull fracture or cochlear implant	S. pneumoniae, H. influenzae, group A beta-hemolytic streptococci	Vancomycin plus ceftriaxone
		Alternative: meropenem plus vancomycin
Patients with penetrating trauma or post neurosurgery	Staphylococcus aureus, coagulase-negative staphylococci, aerobic gram-negative bacilli (including Pseudomonas aeruginosa)	Vancomycin plus cefepime
		Alternative: meropenem plus vancomycin
Patients with cerebrospinal fluid shunt	Coagulase-negative staphylococci, S. aureus, aerobic gram-negative bacilli (including P. aeruginosa), Propionibacterium acnes	Vancomycin plus cefepime