Culture-independent detection systems for bloodstream infection

Background: Sepsis and bloodstream infection are associated with significant morbidity and mortality, and early effective antimicrobial therapy has been demonstrated to improve patient outcomes. Tradi-tional culture-based methods, however, have several limitations that hamper a prompt diagnosis in bloodstream infection, including long turnaround times and limited sensitivity. In recent years, advances have been made in the development of several technologies that allow the identification of pathogens and their resistance markers directly from whole blood, possibly representing promising alternatives to conventional culture-based methods. Objectives: To review the currently commercially available emerging assays for the diagnosis of blood-stream infections directly from whole blood, including their performance and the available data about their impact on patient outcome. Sources: Peer-reviewed publications relevant to the topic have been searched through PubMed; man-ufacturers' websites have also been consulted as a data source. Content: We have reviewed available data about the following technologies: multiplex real-time PCR working directly from whole blood (Magicplex Sepsis Real-Time test, Seegene), PCR combined with T2 Magnetic Resonance (T2Candida and T2Bacteria panel, T2Biosystem), and metagenomics-based assays (including SepsiTest, Molzym; iDTECT Dx Blood, PathoQuest; Karius NGS plasma Test, Karius). Perfor-mance characteristics, advantages and pitfalls of each method are described, and available data about their impact on patients' clinical outcomes are discussed. (C) 2021 Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases.