Accelerated blood culture diagnostic using the bioMérieux Vitek 2
Abstract number: 1134_01_320
Wüllenweber J., Herrmann M.
Identification (ID) and antimicrobial susceptibility testing (AST) from positive blood cultures normally require overnight culture. We evaluated a method to obtain ID and AST within 1 day.
After detection of bacterial growth, 10 ml of each blood culture bottle (Becton Dickinson Bactec) was centrifuged thrice (10 min 500 g to remove erythrocytes, 2 × 5 min 2500 g to remove the supernatant). A suspension with 0.9 McFarland was then inoculated into the bioMérieux Vitek 2. Results of direct ID and AST were compared to those obtained from agar cultures according to manufacturers guidelines.
346 bottles containing 198 gram-positive cocci and 148 gram-negative rods were investigated during a period from December 2003 to July 2004. Identification and AST were excellent for gram-negative rods and enterococci, whereas direct identification of staphylococci required confirmation by other rapid tests (e.g. slide agglutination for clumping factor). AST results showed major discrepancies for 0.2% (gram-negative rods) to 1.2% (gram-positive cocci) of all tested antibiotics.
This method is suitable for same day ID and AST of typical blood cultures isolates. While gram-negative bacilli and enterococci were determined with high accuracy, differentiation between S. aureus and coagulase-negative staphylococci requires complementation by additional techniques.
|Session name:||XXIst ISTH Congress|
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