Off-label use of the BIOFIRE® Blood Culture Identification 2 Panel for multidrug-resistant bacteria colonization surveillance in critical care unit patients: A retrospective study.

In this retrospective, single-center, observational study we assessed the performance of the BIOFIRE® Blood Culture Identification 2 (BCID2) Panel for the identification of multidrug-resistant bacteria (MDRB)-colonized critical care unit patients compared with a standard culture and antimicrobial susceptibility testing (AST)-based approach. A total of 146 rectal/pharyngeal/nasal combined specimens from 130 patients were tested by using the BCID2 panel. MDRB were detected in 40/146 (27.3%) specimens from 39 patients (30%) by the BCID2 panel; MDRB were recovered by culture in 32/146 (21.9%) specimens from 30 patients (23%). Concordance between the MDRB detected by the BCID2 panel and those recovered by culture was observed in 29/43 cases; MDRB were more frequently extended-spectrum beta-lactamase-harboring Enterobacterales or vanA/B-carrying Enterococcus faecium. The per specimen positive and negative percentage agreement values were 90.6% and 90.3%, respectively (Kappa value: 0.73). The BCID2 panel shows promise as a tool for the rapid identification of MDRB carriers in critical care units. Its use may lead to prescription of more refined empirical antimicrobial therapies on an individual basis and allow timely isolation of patients to prevent MDRB spreading. Nevertheless, larger, multicenter, prospective, and Next-generation sequencing-validated studies are needed to corroborate our findings.