Evaluation of the BACTEC 16B medium in a cancer center

The routine use of the new resin-containing BACTEC 16B (Johnston Laboratories, Inc., Cockeysville, MD) culture medium was evaluated in a population consisting primarily of cancer patients. Of 1,163 paired blood culture sets collected, 652 (56%) were collected in the presence of antimicrobial therapy. Eighty-three aerobic and facultatively anaerobic isolates were recovered from 79 positive blood culture sets. No significant difference could be demonstrated between the 16B and the 6B medium in the group of blood cultures collected from patients not receiving antibiotic therapy at the time of blood collection. In contrast, a significantly greater proportion of isolates (P less than 0.005) was recovered from the 16B medium (96%) than the 6B medium (68%) in the group of blood cultures collected in the presence of antimicrobial therapy. In this group, 43% of the isolates were either detected earlier or recovered solely from the 16B medium.