Comparison of BACTEC automated blood culture system and conventional system in hospitalized pediatric patients

A prospective study in pediatric patients compared the BACTEC system, an automated blood culture system using Bactec Ped Plus/F broth media, with the conventional system using Brain Heart Infusion broth media. Each single blood sample drawn for culture from hospitalized children was evaluated by both systems simultaneously. Of 244 pairs of blood samples, 44 (18%) were positive for microorganisms. Of these isolates, 24 (55%) were detected by both systems, 10 (23%) were detected by the BACTEC system only, and 10 (23%) were detected by the conventional system only. The mean turn around time of the BACTEC system (0.56 +/- 0.34, range 0.08-1.55 days) was significantly shorter than that of the conventional system (3.36 +/- 2.72, range 1-7 days, p < 0.001). Seven isolates strongly suspected to be due to contaminants grew out after 5 days of incubation and were detected by the conventional system only. In this study the BACTEC system and the conventional system were equally effective in detecting microorganisms in the patients' blood samples even if antibiotic therapy had been previously administered. However, the results from the BACTEC system were available much sooner and less likely to be contaminants.