emocolture

Emocolture, commonly referred to as a blood culture, is a laboratory procedure in which a blood sample is placed into culture media to detect microorganisms circulating in the bloodstream. The test is used to diagnose bacteremia and fungemia and to guide antimicrobial therapy in suspected systemic infections.

Procedure typically involves obtaining multiple blood samples from one or more venipuncture sites using sterile technique. Most protocols collect two or more sets, each consisting of bottles containing aerobic and anaerobic media. In adults, the total blood volume per set is often 20–30 milliliters, while pediatric samples are smaller. The bottles are incubated in automated culture systems that continuously monitor for growth, with gram stain and organism identification or susceptibility testing performed after growth is detected.

Results are reported as positive or negative. A positive result indicates growth of microorganisms, which are then identified and tested for antibiotic susceptibility to tailor treatment. Common contaminants, especially when detected in a single set, include skin flora such as coagulase-negative staphylococci; clinical correlation is essential to distinguish contaminant from true pathogens. A negative result reduces the likelihood of bacteremia but does not completely exclude infection, particularly if antibiotics were given prior to sampling or if the pathogen is fastidious.

Limitations include reduced yield after prior antibiotic exposure, the time needed for growth (which can range from 24 to 48 hours for many bacteria and longer for fungi), and the inability to detect viral infections. Molecular methods and antigen tests can supplement emocolture in certain clinical scenarios. Emocolture remains a cornerstone in diagnosing bloodstream infections and guiding targeted therapy.