Blood Cultures

General Information

An automated blood culture system is in use. Three bottle types are available:

1. Aerobic (blue top).
2. Anaerobic (purple top).
3. Mycobacteria (red top).

To avoid contamination - ensure the bottle tops are cleaned and disinfected with an isopropyl alcohol swab (steret) before inoculation with blood.

Do not cover or remove the bottle bar code.

A “set” is one aerobic and one anaerobic bottle. A minimum of 10 mL is required for each blood culture bottle. Whenever possible, two blood culture sets should be taken, about 30 minutes apart, prior to the initiation of antibiotic therapy.

If bacterial endocarditis is suspected, 3 separate blood cultures should be taken over a 48 hour period if the clinical condition allows treatment to be delayed.

Blood cultures are incubated for up to 5 days.

Positive blood cultures will be reported to the requesting clinician directly by a Clinical Microbiologist as appropriate.

Negative blood cultures will be reported at 48 hours and again on completion of the 5 day incubation time.

In cases of suspected Brucellosis, blood cultures are incubated for 14 days. Thus, it is important to record on the request form the patient's suspected diagnosis.

If Mycobacterial infection is suspected specific blood culture bottles should be used as detailed above. These are available on request from the laboratory, (extension 16534) and must be transported in the white protective pod as supplied.

These samples must not be sent via the Sample Delivery System, (SDS), please request a porter to deliver samples to the laboratory. These bottles will require extended incubation.

Information Sharing: If your sample needs to be referred or a notifiable disease is detected from your sample, your details and sample may be shared with the UK Health Security Agency (UKHSA). This is a legal requirement. The UKHSA is sponsored by the Department of Health and Social Care.