CLSI M47 A : 1ED 2007

Provides recommendations for the collection, transport, and processing of blood cultures as well as guidance for the recovery of pathogens from blood specimens taken from patients who are suspected of having bacteremia or fungemia.

The laboratory detection of bacteremia and fungemia remains one of the most important functions of
clinical microbiology laboratories. During the past 30 years, a number of studies have defined the critical
factors in the recovery of pathogens from blood and the optimal laboratory methods for recovering
specific pathogens, and have established the performance characteristics of blood culture systems. Despite
this information, there remains a need for guidelines for the collection, processing, and interpretation of
blood cultures.
Several in vitro blood culture devices are cleared by the United States Food and Drug Administration
(FDA) for use in the United States. These devices typically are available for use in other countries.
This guideline is intended to provide guidance to clinical microbiologists and other laboratorians (e.g.,
pathologists, laboratory supervisors, laboratory managers) for the recovery of pathogens from blood
specimens taken from patients who are suspected of having bacteremia or fungemia. Specific
recommendations will be offered for the collection, transport, and processing of blood cultures. The
existing blood culture technology will be reviewed and the relative benefits of these technologies will be
compared. Procedures for the identification of pathogens will not be addressed. Antimicrobial
susceptibility testing of bacteria is addressed in CLSI documents M2—Performance Standards for
Antimicrobial Disk Susceptibility Tests,2 M7—Methods for Dilution Antimicrobial Susceptibility Tests for
Bacteria That Grow Aerobically,3 and M11—Methods for Antimicrobial Susceptibility Testing of
Anaerobic Bacteria.4 Antimicrobial susceptibility testing of fungi is covered in CLSI/NCCLS documents
M27—Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts5 and M38—
Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi.6