Blood cultures with the BACTEC 225 radiometric microbial growth detection system.

The BACTEC 225 automated radiometric blood culture system was compared with a conventional blood culture bottle method for its ability to improve the rapid laboratory diagnosis of bacteremia in cancer patients. The BACTEC 225, in combination with routine blind subcultures and smears of radiometrically negative culture vials, detected two thirds, of all positive cultures within 24 h and shortered the detection time generally by 24-48 h. With the recommended growth index setting of 30, radiometrically false-positive findings are rare and are usually due to leukocytosis resulting from infection or leukemia.