Organism

Bacteremia of unknown source

Neonate (<4 days): Group B streptococcus (GPC), E. coli (GNR), klebsiella (GNR), enterobacter (GNR), S. aureus (GPC), coagulase-negative staphylococci (GPC), Candida sp.

Neonate (>5 days): Add H. influenzae (GNCB).

Child (nonimmunocompromised): S. pneumoniae (GPDC), N. meningitidis (GNDC), S. aureus (GPC), enterococci (GPC).

Adult (IV drug use): S. aureus or viridans streptococci (GPC in chains), enterococci (GPC).

Adult (catheter-related, “line” sepsis): coagulase-negative staphylococci (30%), S. aureus (12%) , Candida sp. (11%), enterococci (9%), other streptococci (9%), Klebsiella pneumoniae (9%), Enterobacter sp. (4%), Serratia sp. (4%), Pseudomonas sp. (4%), Acinetobacter baumanii (1–4%), Corynebacterium jeikeium (1%), other yeast (1%).

Adult (splenectomized): S. pneumoniae, H. influenzae, N. meningitidis.

Neutropenia (<500 PMN/mcL): Enterobacteriaceae, Pseudomonas sp., S. aureus, coagulase-negative staphylococci, viridans streptococci (GPC in chains).

Immunocompromised: Bartonella sp. (GNR), Mycobacterium avium/intracellulare (AFB).