Diagnosis

Should be obtained prior to the initiation of antibiotic therapy for any patient with suspected bacteremia or fungemia.

At least two sets of blood cultures should be obtained from separate venipuncture sites.

Contamination of blood cultures by certain organisms may make it difficult to differentiate between clinical significance and a contaminant.

Common skin contaminants include:

• Coagulase negative staphylococci

• Viridans group Streptococci

• Corynebacterium species

• Propioniobacterium species

• Bacillus (non-anthracis) species

In general, if a typical contaminant is present in one of several other negative blood cultures, and there are no clinical indications for bacteremia, it is likely a contaminant.