New molecular identification test rapidly diagnoses bloodstream infections in ICU patients: PLOS One study

A new molecular identification test has been found to rapidly diagnoses bloodstream infections in ICU patients and shall be a useful tool in the hands of intensivists working in intensive care units.

The use of FA-BCID testing drastically reduced time to optimal antimicrobial treatment in critically ill patients with bloodstream infections, according to a recent study published in the journal PLOS One.

The BioFire FilmArray blood culture identification (FA-BCID) panel is a largely evaluated molecular tool designed to identify 24 microorganisms and 3 antimicrobial resistance genes (mecA, vanA/B and bla_KPC) in 1 hour and 5 minutes directly from the blood of positive culture bottles.

A bloodstream infection (BSI) is caused by the presence of an infective microorganism in the patient's blood and is associated with major mortality and morbidity rates. Rapid detection of the pathogen in the blood culture is required for improving the patient's outcome. Considering the clinical impact of molecular BSI-identification tools, several authors demonstrated a decrease of time to optimal antibiotherapy, a reduced length of hospital stay and a reduced mortality rate compared to phenotypic identification methods.

Alexia Verroken, Université Catholique de Louvain, Brussels, Belgium, and colleagues evaluated how a molecular identification test directly performed on positive blood cultures of critically ill improves patient’s therapeutic management in this pre-post intervention study.

All adult patients in the intensive care unit (ICU) at the time of positive blood culture detection were eligible for the study. The researchers performed standard positive blood culture management in the 8-month pre-intervention period (P0). In the 10-month intervention period (P1) FA-BCID test (bioMérieux) was additionally performed 24/7 at detection. 163 positive blood culture episodes were allocated to P0 and 166 to P1. After the withdrawal of episodes in accordance with defined exclusion criteria, outcome analysis was performed on 110 bloodstream infections both in P0 and P1.

The evaluated clinical outcome was time to optimal antimicrobial treatment of the bloodstream infection. FA-BCID microbiological test performances were also analysed.

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Key findings include:

• Time to optimal antimicrobial treatment in P0 was 14h41 compared to 4h39 in P1. FA-BCID test results led to a treatment adjustment in 35/110 (31.8%) P1 episodes including 26 where the adjustment was the optimal antimicrobial treatment.


• FA-BCID testing identified 96.2% of the on-panel microorganisms thereby covering 85.2% of our ICU-strain epidemiology.


• Time to identification with FA-BCID testing was calculated at 1h35. Resistance detection was in complete concordance with routine results.


• Considering 150 FA-BCID tests were initially performed in P1, 4,3 tests were required to have 1 test leading to an improved therapeutic outcome.

Also Read: Bloodstream infections: Most common type of health care associated infections in children

"FA-BCID could be a beneficial add-on identification tool for diagnosing bloodstream infections in critically ill patients, but they add that further studies are needed in settings with high proportions of multidrug-resistant infections," concluded the authors.

To read the complete study follow the link: https://doi.org/10.1371/journal.pone.0223122