Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1321 page)

   
Turnaround time:
4–8 weeks

   Special Collection and Transport Instructions

   Collect 5–10 mL of blood in sodium polyanethol sulfonate (SPS) or heparin, or directly inoculate specific mycobacterial blood culture media. Inoculate the blood culture media or collection system according to the manufacturer’s instructions. Transport to the laboratory at room temperature.

   Interpretation

   
Expected results:
No growth

   
Positive results:
Mycobacterium avium
complex (MAC) is the most commonly isolated mycobacterial pathogen.
M
.
tuberculosis
may be isolated at the time of hematogenous spread associated with severe primary or reactivation disease. Rapidly growing mycobacteria, such as
M
.
fortuitum
, have been associated with chronic indwelling vascular catheters and other prosthetic material.

   Limitations

   Some mycobacterial infections are rarely associated with mycobacteremia. EDTA or acid citrate dextrose (ACD)-anticoagulated blood should not be used for mycobacterial blood culture inoculum.

Suggested Reading

CLSI.
Principles and Procedures for Blood Cultures; Approved Guideline
. CLSI document M47-A. Wayne, PA: Clinical and Laboratory Standards Institute; 2007.

BLOOD CULTURE, ROUTINE

   Definition and Use

   The routine blood culture is used for detection of bloodstream infections (BSIs) due to common aerobic and anaerobic bacterial and yeast pathogens. Potentially pathogenic isolates are identified, and susceptibility testing is performed, as appropriate. Special testing is required for the detection of mycobacteria, parasites, viruses, and certain fungal pathogens.

   Indications:

   Sepsis syndrome, fever, chills, malaise, hypotension, poor perfusion, toxicity, tachycardia, hyperventilation.