Controlled evaluation of BACTEC Plus 26 and Roche Septi-Chek aerobic blood culture bottles

Blood culture bottles that accept up to 10 ml of blood have recently been introduced for the BACTEC nonradiometric blood culture system. The new formulation, designated BACTEC Plus, contains 25 ml of tryptic soy broth, 0.05% sodium polyanetholesulfonate, and mixed resins. In a collaborative study conducted at three university hospitals, we evaluated the BACTEC Plus 26 (BP26) aerobic bottle and the Roche Septi-Chek aerobic bottle with its agar slide paddle in 5,293 paired blood cultures. Significantly more microorganisms (P less than 0.001), especially Staphylococcus aureus (P less than 0.001), Staphylococcus epidermidis (P less than 0.01), enterococci (P less than 0.005), and members of the family Enterobacteriaceae (P less than 0.005), were detected by the BP26 bottle. When both bottles detected growth, BP26 did so earlier (P less than 0.001). In particular, S. epidermidis (P less than 0.001), streptococci (P less than 0.005), enterococci (P less than 0.05), and members of the family Enterobacteriaceae (P less than 0.001) were detected earlier by the BP26 bottle. We conclude that the BP26 bottle provides a yield and speed of detection of microorganisms superior to those of the Roche Septi-Chek aerobic blood culture bottle.