This is a qualitative test for the detection of microorganisms in body fluids like blood, ascites, cerebrospinal fluid, etc, offering isolated strains to carry out susceptibility tests.
Blood culture is one of the most important and critical procedures performed in the microbiology laboratory. Since blood is normally sterile, the isolation and identification of an organism has great diagnostic significance. Blood culture is of great importance in diagnosing such conditions as endocarditis, typhoid fever, pneumonia and other diseases characterized by bacteremia.
The growth of microorganisms in a blood culture may be delayed or prevented if an anticoagulant is not used in the culture medium since the organisms may become trapped in the fibrin clot. However, some anticoagulants may be toxic for certain pathogens. In addition, many blood samples contain residual antibiotics, antibodies, ß-lysin and phagocytes which are natural bacterial inhibitors and greatly reduce chances of obtaining a positive culture. These obstacles may be overcome by the use of sodium polyanetholsulfonate (SPS), a nontoxic anticoagulant which enables bacterial growth by counteracting or absorbing those natural bacterial inhibitors in blood. Since SPS inhibits the activity of streptomycin, polymyxin B, kanamycin and gentamicin, therapy with these antibiotics should not interfere with microbial growth in blood cultures containing this anticoagulant.
