5309. Bacterial culture. Blood. Aerobes. Anaerobes. Antimicrobial resistance profile with MIC (if microflora is detected)

Blood culture is a bacteriological test, the results of which either confirm its sterility (normal) or detect bacteremia (the presence of bacteria in the blood). Sepsis is usually caused by bacteria resistant to most antibiotics.

A blood culture for sterility with an antibioticogram and determination of the MIC (minimal inhibitory concentration) makes it possible to:

• determine the individual sensitivity of the pathogen to antibiotics;
• select the most effective drug for treatment;
• calculate a personalized dose and administration regimen;
• avoid inadequate empirical therapy and reduce the risk of antibiotic resistance.

Automated identification of microorganisms is performed using MALDI-TOF mass spectrometry on the MALDI Biotyper sirius IVD System analyzer (Bruker, Germany).

Blood culture is one of the most important methods for the diagnosis of sepsis, endocarditis, meningitis, osteomyelitis, pneumonia, peritonitis, postoperative or purulent-inflammatory complications, when there is a risk of infection spreading from a primary focus through the bloodstream.

Under normal conditions, blood is a sterile environment; however, during infectious and inflammatory processes, microorganisms may enter the bloodstream, leading to bacteremia or sepsis.

The purpose of the test is to identify the pathogen that has entered the bloodstream (aerobic or anaerobic) and to determine its antibiotic susceptibility, including the minimum inhibitory concentration (MIC). Interpretation of results is performed in accordance with international EUCAST and CLSI standards.

Important!

To obtain reliable results, blood for culture should be collected before the initiation of antibacterial therapy or after a specified interval following its temporary discontinuation, as recommended by a physician. Blood collection is performed on an empty stomach using venous blood.

It is recommended to avoid blood sampling from venous or arterial catheters due to the high risk of contamination.

The specimen is collected into bottles containing culture media for blood cultures, with valid labeling and expiration dates. The blood volume is 8–10 mL for adults and up to 5 mL for children per bottle.

The biomaterial should be delivered to the microbiology laboratory as soon as possible, preferably within 3 hours. Temporary storage of samples at room temperature is allowed.

Blood culture results should be interpreted exclusively by a physician in the clinical context. They must not be used as a basis for independent initiation or modification of treatment.

• Various types of speciamen depending on the test