Blood Culture
Not yet clinically reviewed
This protocol was migrated from the earlier Pharmapedia and Ward Guide apps for educational use. Follow your hospital's own policies and consult seniors when in doubt.
- Blood culture media are enriched nutrient broth that encourages the multiplication of even one bacterium; hence these media will enhance the growth of any stray contaminating bacterium, such as a normal inhabitant of human skin. Therefore, careful skin preparation before collecting blood sample is of paramount importance.
Method of Collection – Disinfect the puncture site with 70 per cent alcohol followed by 2 per cent iodine (Betadine) keep for 1 minute – (Time is crucial) – Blood samples are inoculated into blood culture media (BHIB, GCB, Bile broth) in 1:5 dilutions. Bile broth when enteric fever is suspected – To ensure maximal recovery, minimum of two sets of blood culture is necessary. Timing and Number of Sample In acute febrile illness – 2 separate samples may be drawn at the same time from different sites. In PUO – Two samples may be drawn an hour or more apart. In Suspected Infective Endocarditis – Three samples, 30 minutes apart from different sites. Volume – 5-10 ml adults, 1-5 ml in children.
Precautions
- Do not touch disinfected puncture site before drawing blood. – Do not collect blood through indwelling IV cannulae line. – In case of delay, keep samples at room temperature or incubate. NEVER REFRIGERATE BLOOD CULTURE SAMPLES FOR BACTERIAL CULTURE Clot Culture (for S. typhi and paratyphi) – Plain blood (5 ml) in sterile container (Separated serum can be used for widal test and clot can be used for culture).