Naslov
FALSE-POSITIVE BLOOD CULTURES DURING BACTERIAL SCREENING OF BLOOD COMPONENTS USING BACT/ALERT SYSTEM

Autori
Vuk, Tomislav ; Batarilo, Ivanka ; Šarlija, Dorotea ; Balija, Melita ; Jukić, Irena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Vox Sanguinis / Takamoto, Shigeru ; Hui, Crystal ; Van Aken, Pim ; Chai, Hoo ; Strengers, Paul - : Willey Blackwell, 2008, 308-308

Skup
International Congress of the ISBT

Mjesto i datum
Macao, Kina, 07.06.2008. - 12.06.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Bact/Alert; false positive

Sažetak
Background. Bacterial screening of blood products (BP) is a routine measure in the evaluation of BP quality. At our Institute it is performed as a part of statistical process control using BacT/Alert 240 microbial detection system (Biomerieux). Through continuious evaluation of the performance and validation studies performed at our QC department this system has proven to be highly sensitive, reliable and easy-to-use. Aims: The aim of this study was to assess the frequency of false-positive blood cultures on BacT/Alert system during bacterial screeening of different BP and using two types of cultivation bottles (glass SA/SN and plastic BPA/BPN). Methods: Quality control data on the bacteriologic control of BP performed in the period 2000-2007 were retrospectively analysed. Sampling and culturing of BP were performed according to Paul-Erlich Institute recommendations. Aerobic and anaerobic bottles with 10 mL of sample were incubated at 360C ± 10C for 7 days. Initially BacT/Alert-positive blood components without bacterial identification in any sample were defined as false positive. Results: A total of 17653 BP were tested for bacterial contamination during the 8-year period (9849 using glass SA/SN bottles, and 7804 using plastic BPA/BPN bottles). 40.2% of tested BP (7089) were PLT concentrates, 37% RBC concentrates (6535), and 22.8% plasma products (4029). Only two RBC concentrates were leucoreduced. Out of 26 false positive blood cultures (corresponding to 26 BP), 16 were detected in aerobic bottles (6 SA and 10 BPA) and 10 in anaerobic bottles (3 SN and 7 BPN). False positive results were more frequent in RBC concentrates (15/26 or 57.7%) in comparison to PLT concentrates (10/26 or 38%). The rate of false positive blood cultures in aerobic bottles was 0.09% (SA 0.06%, BPA 0.13%), and 0.06% in anaerobic bottles (SN 0.03%, BPN 0.09%). Only one false positive result was clearly related to damaged media in the bottle. In all other cases we were not able to determine a cause. Conclusion: Despite top limit of sample volume, the rate of false positive blood cultures in our study is very low, but substantially higher for BPA/BPN bottles in comparison to SA/SN bottles. False positive results were more frequent in RBC concentrates (15/26 or 57.7%) in comparison to PLT concentrates (10/26 or 38%). According to our experience, higher rate of false positives can be expected in non-leukoreduced blood components because of WBC metabolism producing CO2.

Izvorni jezik
Engleski

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