Optimum Time to Detection of Bacteria and Yeast Species with BACTEC 9120 Culture System from Blood and Sterile Body Fluids

• Main Authors: Nita Pal, Rajni Sharma, Suman Rishi, Leela Vyas
• Format: Article
• Language: English
• Published: Thieme Medical and Scientific Publishers Pvt. Ltd. 2009-07-01
• Series: Journal of Laboratory Physicians
• Subjects: automated blood culture system; bactec; time to detection
• Online Access: http://www.thieme-connect.de/DOI/DOI?10.4103/0974-2727.59703

The culture results of 4,807 blood and 383 sterile body fluid specimens received in our laboratory during a 54-month period, were analyzed to determine the time required for culture to become positive, time at which a culture could safely be considered negative, and the spectrum of isolated organisms. The specimens were processed by automated BACTEC 9120 culture system. A total of 1,677 clinically significant microorganisms were isolated. Gram positive and negative bacterial isolation rates were found to be 62.55% and 32.20%, respectively. Yeasts were recovered in 5.24%. False positivity rate was 1.5%. Clinically significant isolates recovered on day four and five were 97.81% and 99.88%, respectively. At day five, the sensitivity was 99.94% and negative predictive value 99.96%. Our data support a five-day incubation protocol for recovery of all clinically significant organisms with sensitivity reduced by 0.06%, when compared with a six-day protocol.