[Efficiency and Usefulness of the Molecular Test 'Biofire®Filmarray® Blood Culture Identification 2' in the Quick Diagnosis of Bacteraemias in a Burns Intensive Care Unit].

Abstract

The occurrence of bacteremia during a hospital stay worsens the prognosis of patients. Especially in burn patients, it is one of the most severe infectious complications during their stay in intensive care units, with high mortality rates. Consequently, rapid detection of the pathogens responsible is crucial for the prompt initiation of effective antimicrobial therapy. In our study, we analysed 85 positive blood cultures collected from 66 patients hospitalised in the burns unit and presenting criteria for sepsis. The results of the molecular test FilmArray BCID2 were compared with those of conventional microbiology methods. Overall, the results of the BCID2 panel were concordant with those of conventional culture in 71.8% of cases. For monomicrobial cultures, the concordance of identification was 83.9%, while for polymicrobial cultures the concordance was 36.4%. The test showed a good performance in the detection of pathogens, with an overall sensitivity of 84.5% and specificity of 98.3%; for the panel targets these rates rose to 95.4% and 98.1% respectively. For resistance genes, the BCID2 detected the blaCTX-M gene in 9 enterobacteria and the carbapenemase genes: blaNDM, blaOXA-48- like, blaVIM in 20 BGN. The mecA/C gene was isolated from 5 Staphylococcus epidermidis and for vancomycin-resistant Enterococcus the vanA/B gene was detected in 3 Enterococcus faecuim. The sensitivity and specificity of the test for detecting resistance genes were 84.1% and 92%. The turnaround time (TAT) for molecular test results was 1 hour and 10min (Q1 1.09 h; Q3 1.12 h). The median TAT for BCID2 was significantly (Mann-Whitney, p<0.0001) shorter than for conventional culture 39.1 h (Q1 33 h; Q3 57.6 h). Antimicrobial therapy was modified on the basis of the molecular test results in 35.3% of patients. This was done within a median of 04 hours of receiving the test result [interquartile range 2.4h - 21h]. A favorable outcome was noted in 70% of these patients.