Generality
Blood culture is a microbiological test aimed at isolating and identifying any microorganisms present in the blood; for this reason it is commonly associated with the pharmaceutical susceptibility test of the detected pathogens (see antibiogram). All this guarantees a targeted and effective therapeutic intervention , avoiding useless or harmful antibiotic therapies, both for the subject and for the community.
What's this
Blood culture consists in sowing a blood sample, taken by venipuncture, on special culture media. This analysis is aimed at searching for and identifying one or more microorganisms (especially bacteria or yeasts) responsible for an infection, and then determining its sensitivity to antibiotics.
Note
Infections of the bloodstream are most commonly of bacterial origin (bacteremia), but can also be caused by fungi (fungemia) or viruses (viraemia).
The "possible presence of germs in a" blood culture (therefore in the blood of the patient being examined) indicates that a septicemia is in progress. If this latter condition is accompanied by an infectious syndrome it is called sepsis.
Because it is measured
Blood culture is used to establish the presence of a systemic, sometimes life-threatening infection. Usually, the source of this complication is located in a specific site of the organism; its diffusion in the blood is favored by the compromise of the immune system, as well as by the location and severity of the infectious process.
Blood culture allows you to:
- Evaluate the presence of bacteria or fungi in the bloodstream (ie search for the etiological agents responsible for the infection in progress);
- Formulate the microbiological diagnosis of sepsis and / or fever of unknown origin;
- Create an antibiogram to guide the doctor in prescribing effective antibiotic treatment.
Normally, several blood samples are collected to carry out the examination, from different veins of the two arms. In this way it is possible to increase the probability of detecting bacteria and fungi that may be present in small quantities or that can enter the bloodstream in intermittently. This procedure also ensures that the pathogenic microorganisms detected are not attributable to a contamination of the sample, but really represent the cause of the infection.
