Pediatric blood culture evaluation of the BACTEC PEDS Plus and the DuPont Isolator 1.5 systems.

A new nonradiometric BACTEC medium has been developed for culturing pediatric blood samples. The BACTEC PEDS Plus medium (BACTEC PED) consists of 20 ml of an enriched broth with resins. In contrast to the other aerobic BACTEC media, there is a lower concentration of sodium polyanetholesulfonate in the medium and more CO2 in the headspace of the vial. This study was conducted in two different pediatric settings to compare the performance of the BACTEC PED medium with the Du Pont Isolator 1.5 system (ISO 1.5) in terms of overall organism recovery and time to detection. Equal volumes of up to 1.5 ml were tested in both systems. A total of 4063 culture sets were analyzed, yielding 301 (7.4%) clinically significant isolates. Of these, 86 (29%) were recovered only from the BACTEC PED and 12 (4%) only from the ISO 1.5 (p less than 0.001). BACTEC PED recovered significantly more staphylococci and Enterobacteriaceae than ISO 1.5 (p less than 0.001 and p less than 0.005, respectively). Detection times of isolates recovered in both systems were comparable. For those patients on antibiotic therapy at the time of culture, 21 (37%) were positive only in the BACTEC PED, whereas two (4%) were positive only in the ISO 1.5. The nontherapy group had 61 (27%) organisms that were detected in BACTEC PED only and 9 (4%) in ISO 1.5 only. These results indicate that BACTEC PED is a significant advance in blood culture systems that will provide a sensitive method for detecting pediatric bacteremias.