Journal des troubles sanguins et de la transfusion

Abstrait

Measurement of BacT/ALERT Sensitivity after Inoculation Certain Amount of E. coli and S. epidermis

Abolfazl Dabirmoghadam, Farhad Razjou and Bahram A. Badlou

Background: Transfusion of contaminated human platelets concentrates (PCs) causes septic reaction and death of recipients. Current rate of detection of bacterial-contaminated of the PCs are very important tools to warranty patients’safety. BacT/ALERT system was introduced as one of the most sensitive, specific, and rapid screening test, which could be implemented in Blood Transfusion Centers. The aim of this study is to investigate whether the BacT/ALERT system as introduced, can function as rapid detection system.

Material and Methods: In this study we used the whole blood from 24 healthy human subjects with inform consent, The PCs were collected from these whole blood samples by differential Centrifugation and Buffy coat system. All PCs (50-70 mL) stored under standard blood banking conditions. The PCs were randomly selected and divided in two groups of 12, and 10 CFU/mL was of either E. coli (gram negative) added into first group (n=12 PCs), or S. epidermidis (gram positive) bacteria into another group (n=12 PCs). Then samples were inoculated in BPA culture medium of BacT/ALERT system and studied after 0, 6, 24, 48 hrs.

Results: The BacT/ALERT system showed rapidly positive results with E. coli samples (T0) with all introduced volumes (0.5,1, 2 ml) but with S. epidermidis samples showed 83% with low volumes (0.5 and 1 ml), and 91.6% positive alert results with high volume (2 ml) after 48 hrs incubations.

Conclusion: This indicates that the sensitivity and specificity of BacT/ALERT system is disputable and not universal, which remained to be investigated in details.