Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation

Article Article scientifique Article Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation eng 2022-09-29 2022-10-19 author Cherkaoui Abdessalam 0000-0002-1801-5935 Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 504646 Département de médecine (DEMED) author Schorderet Didier Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland author Azam Nouria Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 134765 author Crudeli Luigi Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 949236 author Fernandez José Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 501823 author Renzi Gesuele Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 111073 author Fischer Adrien Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 403596 author Schrenzel Jacques Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland 29184 Département de médecine (DEMED) e00898-22 10.1128/jcm.00898-22 36173195 0095-1137 PMC9580353 https://journals.asm.org/doi/10.1128/jcm.00898-22 The objective of this study was to evaluate the accuracy and robustness of a fully automated EUCAST RAST (rapid antimicrobial susceptibility test) directly from positive blood culture and to appreciate its implementation constraints. This study was conducted in two phases: (i) spiked blood culture bottles (BCs) using 779 non-duplicate clinical isolates and (ii) a prospective clinical trial including 534 positive BCs sequentially processed in routine at the Bacteriology Laboratory of Geneva University Hospitals. The RAST results were assessed against EUCAST standardized disk diffusion testing results. Our first finding was that the results of the spiked BCs precisely predicted the clinical trial results. The overall categorical agreements for all species analyzed were greater than 95% at the different time points. RAST for Pseudomonas aeruginosa, however, raised several challenges. The categorical agreement for imipenem was lower than 95% at 6 h and was not improved with longer incubation times. Additionally, piperacillin-tazobactam, ceftazidime, and cefepime cannot be released at 6 h due to suboptimal performances, but the categorical agreement substantially improved at 8 h. Our results establish that the performance of fully automated EUCAST RAST directly from positive blood culture bottles is consistently robust, even for the detection of extended-spectrum β-lactamase (ESBL), carbapenemase-producing bacteria, and methicillin-resistant Staphylococcus aureus (MRSA). The automation markedly enhanced the percentage of readable inhibition zones and reduced the percentage of isolates categorized in the area of technical uncertainty (ATU). In summary, a fully automated EUCAST RAST can substantially improve laboratory workflow by reducing hands-on time and removing the strong constraints linked to manual read-outs at precisely defined times. AST Copan Radian EUCAST RAST RAST WASPLab Blood cultures Full automation Anti-Bacterial Agents / pharmacology Anti-Bacterial Agents / therapeutic use Blood Culture Cefepime Ceftazidime Humans Imipenem Methicillin-Resistant Staphylococcus aureus Microbial Sensitivity Tests Piperacillin Prospective Studies Tazobactam Beta-Lactamases Dewey 616 56 Département de médecine 221 false 338 Génomique et microbiote 604 Journal of clinical microbiology 60 10 36aae544-fd66-4021-b453-69c268340f75 Article (Published version) Public Article-scientifique-from-crossref.pdf 252102 application/pdf CC BY-4.0 2422d5d0ed2875702eb811cdd204b132ef01ec11d23dc2303348f9373cd4abb4 79a3c2ac-9139-41c5-bdf3-e823d28c056e Appendix Public jcm.00898-22-s0001.pdf 1691414 application/pdf 715f7dd01664bbf0973d282df9849139e76912806b8f5006acce9e359d842e13 openAccess Faculté de médecine / Section de médecine clinique / Département de médecine

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Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation	Journal of clinical microbiology			2022	104	521

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Crudeli, Luigi