Rapid identification of positive blood cultures enables early directed antimicrobial therapy with associated reduction in mortality and duration of hospital stay. This study assesses the utility of the BioFire FilmArray® Blood Culture Identification (BCID) Panel (bioMérieux) as a qualitative multiplexed PCR assay capable of the simultaneous detection of 24 potential pathogens as well as 3 genes encoding for antimicrobial resistance (mecA, vanA/B, blaKPC), directly positive blood culture broth.
Positive blood culture broth with organisms seen by Gram stain (n=70), collected from patients between September 2017 to January 2018 were included in the study and tested according to manufacturer’s instructions. All results were compared to routine standard bacterial culture on solid agar plates, bacterial identification of isolated colonies by matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) using the Bruker MALDI Biotyper® (Bruker Daltonics), and existing in-house PCR for antimicrobial resistance.
Compared to standard culture and in-house PCR methods, 94.2% (66/70) of positive blood culture broths were concordant. 107 targets were detected whereby 96.3% (103/107) were concordant including 10 polymicrobial blood culture specimens. 2 false negatives (mecA =1; E. cloacae complex =1) and 2 false positives (E. coli = 1; K. pneumoniae = 1) were observed.
The FilmArray® BCID Panel is able to provide rapid results in approximately 1 hour from when a positive blood culture has flagged positive, providing results approximately 14 hours earlier compared to our existing methods. Based on a review of positive blood cultures at Nepean Hospital in 2017, 86.6% of isolates identified had the potential to be detected on the BCID Panel. Overall we believe it to be a useful tool in aiding early administration of targeted therapy, with the potential to reduce hospital costs and patient stay when used in conjunction with other laboratory and clinical findings.