ABSTRACT
The ability to rapidly detect the presence of microorganisms in the bloodstream of a patient with an invasive, life-threatening infection is truly one of the most important functions of the clinical microbiology laboratory. This responsibility was recognized early in the 20th century but from an historical perspective, the report of Scott in 1951 (1), which described a modification of the Casteneda blood culture technique (2), is considered to represent the birth of the modern day blood culture method. Numerous adaptations of this protocol have been reported since Scott's publication but the basic design, that consists of two complementary bottles ofbroth media and head-space atmospheres so fashioned to optimize the recovery of aerobic and anaerobic microorganisms from blood, remains the mainstay of blood culture technology today. The evolution of blood culture systems has advanced considerably over the past fifteen years but the basic principles have not changed. During this most recent period of development, greater emphasis was placed on instrumentation and automation of the blood culture process. With the advent of immunosuppressive therapy, opportunistic infections, and biomedical implants, however, a new responsibility has been placed on the microbiology laboratory, i.e., to determine whether microorganisms recovered from blood are actually involved in the disease process or were accidentally introduced into the culture media during specimen procurement or inoculation.
