CAP Pro Course - Microbiology - Blood Cultures

(based on 558 customer ratings)

Author: Amber E. Cochran, PhD (ABD), MPH, MLS(ASCP)
Reviewer: Hallee Waye, BS, MLS (ASCP)CM

Continuing Education Credits

Objectives

  • Describe the reasons for drawing a blood culture, including proper collection methods to maximize yield and minimize contamination.
  • Identify factors that optimize recovery of pathogens, including the proper interval between draws, amount of blood necessary per draw, appropriate number of blood cultures, and appropriate media to inoculate/number of bottles to include.
  • Identify the source and incidence of the most frequently isolated pathogens in bacteremia, septicemia, endocarditis, and catheter-related infections.
  • Define methods of identification for positive blood cultures and report results appropriately.
  • Provide methods for determination of clinical relevance of isolates identified in positive blood culture bottle and rule out contaminants.
  • Demonstrate special methods that are necessary to isolate fastidious microorganisms.

Course Outline

  • Describe the reasons for drawing a blood culture, including proper collection methods to maximize yield and minimize contamination.
      • Types of Bloodstream Infections
      • Reasons for Requesting Blood Culture Collection
      • Collection of Blood by Venipuncture
      • Blood Culture Collection Methods That Maximize Yield and Minimize Contamination
      • What is the preferred method of blood culture collection?
      • What antiseptic is recommended to kill surface and subsurface bacteria on the skin prior to blood culture collection?
  • Identify factors that optimize recovery of pathogens, including the proper interval between draws, amount of blood necessary per draw, appropriate number of blood cultures, and appropriate media to inoculate/number of bottles to include.
      • Timing of Blood Culture Collection
      • Volume of Blood and Number of Cultures Collected
      • Manual Blood Culture Systems: Media, Examination, and Timeline
      • Automated Blood Culture Systems: Benefits and Examination
      • Automated Blood Culture Systems: Timeline and Media
      • Subculture of Positive Blood Cultures
      • When endocarditis, vascular infections, or device-associated (eg, catheter-related) infections are suspected and it is necessary to document continuou...
      • When using automated systems for routine monitoring of blood cultures, how many days are blood cultures generally held for?
      • The amount of blood that can be safely collected for blood cultures depends upon which factor?
  • Identify the source and incidence of the most frequently isolated pathogens in bacteremia, septicemia, endocarditis, and catheter-related infections.
      • Most Commonly Isolated Pathogens: Bacteremia/Septicemia
      • Most Commonly Isolated Pathogens: Endocarditis
      • Most Commonly Associated Pathogens: Catheter-Related Bacteremia/Septicemia
      • Which organism is most likely to be associated with transplant patients?
      • The introduction of vaccinations in children has reduced the number of bloodstream infections associated with which organism?
      • Which organism (present in the image) is commonly associated with catheter-related bacteremia/septicemia?
  • Define methods of identification for positive blood cultures and report results appropriately.
      • Conventional Methods for the Identification of Blood Cultures Positive for Gram-Positive Organisms
      • Conventional Methods for the Identification of Blood Cultures Positive for Gram-Negative Organisms
      • Rapid Methods for the Identification of Positive Blood Cultures
      • Performing Antimicrobial Susceptibility Testing (AST)
      • Providing Preliminary Blood Culture Results
      • Providing Interim Blood Culture Results
      • Final Reporting of Positive Blood Cultures
      • Critical Value Reporting
      • For which organism should antimicrobial susceptibility testing (AST) always be performed when isolated from a positive blood culture?
      • When reporting positive blood culture results, all of the following information should be included in the interim report, except?
      • While working up a gram-positive bacillus that is growing aerobically in a positive blood culture, which select agent of bioterrorism must be ruled-ou...
      • A subculture is performed from a positive blood culture and Streptococcus pyogenes (group A strep) is highly suspected. Which test can be performed to...
  • Provide methods for determination of clinical relevance of isolates identified in positive blood culture bottle and rule out contaminants.
      • Contamination
      • Common Skin Flora Contaminants
      • Monitoring the Contamination Rate
      • Calculating the Contamination Rate
      • Which bacteria is often considered a skin flora contaminant when isolated from a single blood culture bottle?
      • The contamination rate for blood cultures should be less than which percentage?
      • The total number of blood cultures collected in your institution for the month of July was 1,338. Of this total, 57 of those cultures were contaminate...
  • Demonstrate special methods that are necessary to isolate fastidious microorganisms.
      • Commonly Requested Blood Cultures for Fastidious Bacteria and Media Needed for Recovery
      • Commonly Requested Blood Cultures for Fungi, Mycobacterium, and Viruses
      • Which of these fastidious organisms are not able to be recovered using routine blood culture isolation methods, even when extending the incubation tim...
      • Fungal cultures are incubated at which temperature for optimal recovery?
      • The Gram stain from a blood culture bottle is positive for yeast, but nothing grows out on subcultures plated on fungal media. Which of the following ...
  • References
      • References

Additional Information

Level of Instruction: Intermediate
Intended Audience: This program is designed as an educational and training tool for MLS, MT, and MLT personnel, medical laboratory science students and interns, pathology residents, and practicing pathologists.
Author Information: Amber E. Cochran, PhD(ABD), MPH, MLS(ASCP) received a Bachelor's in Medical Technology from Georgia Reagents University in Augusta, Georgia. She attended Walden University and completed a Master's in Public Health. Amber is working on her dissertation to receive her PhD in Public Health. Amber was previously the Clinical Laboratory Manager in the Bacteriology Unit at the Georgia Public Health Laboratory in Decatur, Georgia and is currently the Molecular Microbiology Supervisor for Florida Womancare Laboratory in Tampa, Florida.
Reviewer Information: Hallee Waye, BS, MLS (ASCP)CM, has over 10 years of experience as a medical laboratory scientist. She has clinical experience in blood bank, microbiology, chemistry, hematology, urinalysis, and coagulation. She currently works as a clinical microbiologist and MLS Program Director for the Parkview School of Medical Laboratory Science in Pueblo, CO. She obtained her bachelor’s degree in microbiology from Colorado State University, attended the Colorado Center for Medical Laboratory Science to obtain her professional certificate in medical laboratory science, and completed her master’s degree in clinical laboratory science at the University of Texas Rio Grande Valley.

This course is part of the CAP Competency Assessment Hub.

See other included Pro courses

See other included instrument checklists