Optimum detection times for bacteria and yeast species with the BACTEC 9120 aerobic blood culture system: Evaluation for a 5-year period in a Turkish university hospital

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Durmaz G., Us T., Aydinli A., Kiremitci A., Kiraz N., Akgun Y.

JOURNAL OF CLINICAL MICROBIOLOGY, vol.41, no.2, pp.819-821, 2003 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 41 Issue: 2
  • Publication Date: 2003
  • Doi Number: 10.1128/jcm.41.2.819-821.2003
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.819-821
  • Eskisehir Osmangazi University Affiliated: Yes


We tracked and documented the time of positivity of blood cultures by using the BACTEC 9120 (Becton Dickinson Diagnostic Instrument Systems) blood culture system over a 5-year study period. A 7-day protocol of the incubation period was selected, and a total of 11,156 blood cultures were evaluated. The clinically significant microorganisms (32.95%) were isolated in 3,676 specimens. Gram-positive and -negative bacterial isolation rates were found to be 41.07 and 44.88%, respectively. Yeasts were found in 14.03% of all pathogens. Both the false-positivity and -negativity rates were very low (0.1 and 0.3%, respectively). The mean detection times for all of the pathogens were determined to be 19.45 h. Yeasts, nonfermentative gram-negative bacteria, and Brucella melitensis strains were isolated within 5 days. By taking these data into account, we decided to establish a 5-day-incubation protocol in our laboratory instead of the 7 days that are commonly used.