Evaluation of the BACTEC resin blood-culture medium

A study to determine the value of the BACTEC resin-containing medium, 16B, used in conjunction with radiometric detection of bacteremia using three media was conducted. During a six-month period, 2,104 blood-culture sets consisting of the four media (6B, 7C, 8B, and 16B) were collected. There were 158 significant positive cultures (excluding contaminants) that yielded 168 pathogenic isolates. The data were divided into two patient groups: patients receiving antibiotics and patients not receiving antibiotics. In contrast to previous studies, there was no significant difference in the detection rate of significant positive cultures by the different media in either group of patients. However, in patients receiving antimicrobial therapy, 41 of 55 significant positive cultures (74.5%) were detected by 16B medium, while 34 of 55 (61.8%) were detected by 6B medium. Although this difference is not statistically significant, this trend suggests that 16B medium may be useful in these patients. However, the isolation rate of significant positive cultures is the same for the resin medium and the hypertonic aerobic medium for both groups of patients. Thus, it is possible that the hypertonic medium is as efficacious as resin-containing media in blood culturing.