Diagnostic accuracy of rapid molecular tests for detecting antimicrobial resistance in bloodstream infections: a systematic review

Background: Rapid molecular tests (RMTs) accelerate antimicrobial resistance detection in bloodstream infections, and accuracy differs by target. This systematic review evaluated diagnostic performance. Methods: We searched PubMed, Scopus, Web of Science, and Embase for original studies assessing RMTs for resistance detection in bloodstream infections (BSIs) using positive blood cultures or whole blood. Eligible studies compared assays with conventional microbiology, phenotypic susceptibility testing, molecular methods, or combined standards. We extract data on assay characteristics, resistance targets, diagnostic outcomes, turnaround time, and clinical impact. Results: We include nine studies involving 2,439 samples. Platforms included FilmArray/BCID, Verigene BC-GP/BC-GN, BIOFIRE BCID2, T2Resistance, and the Molecular Mouse System. Performance was high for covered organisms and resistance markers. BCID2 showed 98.9% sensitivity and 99.6% specificity for organism targets, with 97.9% positive percent agreement and 99.9% negative percent agreement for resistance determinants. T2Resistance showed 100% sensitivity for several genes and shorter time to detection than conventional methods. Lower performance was reported in polymicrobial cultures and when resistance mechanisms were outside assay panels. Conclusion: RMTs are adjuncts for early resistance detection in BSIs and shorten time to results. They should complement conventional culture and susceptibility testing because limited target coverage, off-panel organisms, and imperfect genotype-phenotype correlation is important constraints.