Comparison of the Roche Septi-Chek blood culture bottle with a brain heart infusion biphasic medium bottle and with a tryptic soy broth bottle.

In a comparison of 1,368 positive blood cultures, a vented Roche Septi-Chek (V-RSC) blood culture bottle was superior to an unvented tryptic soy broth-containing bottle (Difco) for the recovery of all aerobic and facultatively anaerobic microorganisms. Anaerobic bacteria were recovered more frequently and earlier in the unvented tryptic soy broth-containing bottle. A separate comparison of 529 positive blood cultures was conducted to examine the performance of the V-RSC bottle with that of a vented brain heart infusion biphasic medium. The V-RSC bottle recovered significantly more isolates of Enterobacteriaceae and of anaerobic bacteria than did the vented brain heart infusion biphasic medium. The V-RSC bottle is a reliable blood culture system for all aerobic and facultatively anaerobic microorganisms. Because of its suboptimal recovery of anaerobic bacteria, it is recommended that the V-RSC bottle be used in combination with an unvented vacuum blood culture bottle.