Novel rapid diagnostic system for pathogen identification and antimicrobial susceptibility testing: clinical utility in ICU patients with sepsis

This study aimed to evaluate a molecular diagnostic system for the rapid identification of pathogens and determination of their antimicrobial susceptibility. By comparing its performance with standard microbiological methods, the study assessed whether the new system could shorten the time to optimal antimicrobial therapy and reliably complement, or potentially replace, conventional diagnostics. A retrospective study was conducted to evaluate the performance of the Accelerate Pheno system (ACC), a platform for rapid microorganism identification (ID) and antimicrobial susceptibility testing (AST), in comparison with standard-of-care (SOC) laboratory methods for positive blood cultures. The study included adult patients diagnosed with sepsis admitted to the Intensive Care Unit (ICU) who had a positive blood culture result. The total turnaround time (from ICU blood sample collection to the availability of both ID and AST results) was significantly reduced from approximately 3 days with SOC methods to 29 h with the ACC system (p < 0.001). In 67% of cases clinical decisions regarding antimicrobial therapy were guided by ACC results: de-escalation in 20%, escalation in 37%, and no changed in 43%; in the remaining 33% of cases, decisions were based on SOC results. Pathogen ID using ACC system was successful in 68% of samples, while in 32% of cases no complete result was obtained. Failure to identify pathogens was due to limitations of the detection panel, partial identification in polymicrobial samples, or technical errors of the system. AST comparison between ACC and SOC methods showed full concordance for Gram-positive organisms. Among Gram-negative bacteria, 95% of AST results were concordant, with discrepancies observed in 5% of determinations, including three very major errors, four major errors, and four minor errors. The evaluated system substantially shortened the time to pathogen identification and susceptibility reporting. Although complete results were not achieved in all clinically relevant cases, the system demonstrated high concordance with standard methods. Despite some limitations, particularly in pathogen coverage and performance in polymicrobial samples, the system proved to be a valuable complementary diagnostic tool. Its implementation can enhance laboratory efficiency and support earlier, targeted antimicrobial therapy in the management of sepsis.