Blood culture contamination

Never bacteremia
- Corynebacterium
- Bacillus, except B. anthracis
- Propionobacterium acnes
Almost never bacteremia
Always true bacteremia
- Staphylococcus aureus
- Streptococcus pneumoniae
- Escherichia coli
- Enterobacteraciae
- Pseudomonas aeruginosa
- Candida albicans
Coagulase-negative staphylococci are rarely significant (12%), but because they are so common (70-80% of all positive cultures), they are the most common cause of bacteremia.