Influence of a blood culture inoculation technique on detection of bacteremia by the BACTEC system.

A 2-year study compared the influence of blood culture inoculation technique on the detection of bacteremia by an automated radiometric system (BACTEC; Johnston Laboratories, Inc.). A total of 4,690 specimens (20 ml each) were collected. Of each sample, 10 ml was inoculated into a pair of Bactec bottles at the bedside (BACTEC system). The remaining 10 ml was placed in an evacuated blood collection tube (VACUTAINER; Becton Dickinson VACUTAINER Systems) and transported to the laboratory for subsequent inoculation into an identical set of vials (VACUTAINER-BACTEC system). A total of 309 cultures grew organisms considered to be clinically significant. The recovery rate, time to positivity, and spectrum of isolates were similar for the two methods. There were substantially more sporeforming "contaminants" isolated in the VACUTAINER-BACTEC system.