Evaluation of the Accelerate Pheno System: Results from Two Academic Medical Centers.

Rapid diagnostic tests are needed to improve patient care and to combat the problem of antimicrobial resistance. The Accelerate Pheno system (Accelerate Diagnostics, Tucson, AZ) is a new diagnostic device that can provide rapid bacterial identification and antimicrobial susceptibility test (AST) results directly from a positive blood culture. The device was compared to the standard of care at two academic medical centers. There were 298 blood cultures included in the study, and the Accelerate Pheno system provided a definitive identification result in 218 instances (73.2%). The Accelerate Pheno system provided a definitive and correct result for 173 runs (58.1%). The Accelerate Pheno system demonstrated an overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 94.7%, 98.9%, 83.7%, and 99.7%, respectively. An AST result was available for analysis in 146 instances. The overall category agreement was 94.1% with 12 very major errors, 5 major errors, and 55 minor errors. After a discrepancy analysis, there were 5 very major errors and 4 major errors. The Accelerate Pheno system provided an identification result in 1.4 h and an AST result in 6.6 h; the identification and AST results were 41.5 h and 48.4 h faster than those with the standard of care, respectively. This study demonstrated that the Accelerate Pheno system is able to provide fast and accurate organism identification and AST data. A limitation is the frequency with which cultures required the use of alternative identification and AST methods.

Lutgring JD ，Bittencourt C ，McElvania TeKippe E ，Cavuoti D ，Hollaway R ，Burd EM ... -  《-》

Multicenter Evaluation of the Accelerate PhenoTest BC Kit for Rapid Identification and Phenotypic Antimicrobial Susceptibility Testing Using Morphokinetic Cellular Analysis.

We describe results from a multicenter study evaluating the Accelerate Pheno system, a first of its kind diagnostic system that rapidly identifies common bloodstream pathogens from positive blood cultures within 90 min and determines bacterial phenotypic antimicrobial susceptibility testing (AST) results within ∼7 h. A combination of fresh clinical and seeded blood cultures were tested, and results from the Accelerate Pheno system were compared to Vitek 2 results for identification (ID) and broth microdilution or disk diffusion for AST. The Accelerate Pheno system accurately identified 14 common bacterial pathogens and two Candida spp. with sensitivities ranging from 94.6 to 100%. Of fresh positive blood cultures, 89% received a monomicrobial call with a positive predictive value of 97.3%. Six common Gram-positive cocci were evaluated for ID. Five were tested against eight antibiotics, two resistance phenotypes (methicillin-resistant Staphylococcus aureus and Staphylococcus spp. [MRSA/MRS]), and inducible clindamycin resistance (MLSb). From the 4,142 AST results, the overall essential agreement (EA) and categorical agreement (CA) were 97.6% and 97.9%, respectively. Overall very major error (VME), major error (ME), and minor error (mE) rates were 1.0%, 0.7%, and 1.3%, respectively. Eight species of Gram-negative rods were evaluated against 15 antibiotics. From the 6,331 AST results, overall EA and CA were 95.4% and 94.3%, respectively. Overall VME, ME, and mE rates were 0.5%, 0.9%, and 4.8%, respectively. The Accelerate Pheno system has the unique ability to identify and provide phenotypic MIC and categorical AST results in a few hours directly from positive blood culture bottles and support accurate antimicrobial adjustment.

Pancholi P ，Carroll KC ，Buchan BW ，Chan RC ，Dhiman N ，Ford B ，Granato PA ，Harrington AT ，Hernandez DR ，Humphries RM ，Jindra MR ，Ledeboer NA ，Miller SA ，Mochon AB ，Morgan MA ，Patel R ，Schreckenberger PC ，Stamper PD ，Simner PJ ，Tucci NE ，Zimmerman C ，Wolk DM ... -  《-》

Clinical Effect of Expedited Pathogen Identification and Susceptibility Testing for Gram-Negative Bacteremia and Candidemia by Use of the Accelerate Pheno(TM) System.

Fast diagnostic tests providing earlier identification (ID) of pathogens, and antimicrobial susceptibility testing (AST) may reduce time to appropriate antimicrobial therapy (AAT), decrease mortality, and facilitate antimicrobial deescalation (ADE). Our objective was to determine the theoretical reduction in time to AAT and opportunities for ADE with Accelerate PhenoTM System (AXDX). The prospective cohort (April 14, 2016 through June 1, 2017) was from the Barnes-Jewish Hospital, a 1250-bed academic center. Emergency department (ED) or intensive care unit (ICU) blood cultures Gram-stain positive for gram-negative bacilli (GNB) or yeast. AXDX was used in parallel with standard-of-care (SOC) diagnostics to determine differences in time to pathogen ID and AST. Theoretical opportunities for ADE from AXDX results were determined. In total, 429 blood cultures were screened, 153 meeting inclusion criteria: 110 on-panel GNB, 10 Candida glabrata, and 5 Candida albicans. For GNB SOC, median time from blood culture positivity to ID and AST were 28.2 and 52.1 h. Median time to ID and AST after AXDX initiation was 1.37 and 6.7 h for on-panel organisms. For on-panel Candida, time to ID was approximately 21 h faster with AXDX. ADE or AAT was theoretically possible with AXDX in 48.4%. Of on-panel organisms, 24.0% did not receive initial AAT. In-hospital mortality was 46.7% without initial AAT, and 11.6% with AAT. Coverage of AXDX was 75.3%, specificity 99.7%, positive predictive value (PPV) 96.0%, and negative predictive value (NPV) 97.6%. On-panel sensitivity was 91.5%, specificity 99.6%, PPV 96.0%, and NPV 99.0%. AXDX provides more rapid ID and AST for GNB and ID for yeast than SOC. AXDX could potentially reduce time to AAT and facilitate ADE.

Burnham JP ，Wallace MA ，Fuller BM ，Shupe A ，Burnham CD ，Kollef MH ... -  《-》

Systematic Evaluation of the Accelerate Pheno System for Susceptibility Testing of Gram-Negative Bacteria Isolated from Blood Cultures.

Patel YA ，Kirn TJ ，Weinstein MP ，Uprety P ... -  《Microbiology Spectrum》

Evaluation of the Accelerate Pheno System for Fast Identification and Antimicrobial Susceptibility Testing from Positive Blood Cultures in Bloodstream Infections Caused by Gram-Negative Pathogens.

Bloodstream infections (BSI) are an important cause of morbidity and mortality. Increasing rates of antimicrobial-resistant pathogens limit treatment options, prompting an empirical use of broad-range antibiotics. Fast and reliable diagnostic tools are needed to provide adequate therapy in a timely manner and to enable a de-escalation of treatment. The Accelerate Pheno system (Accelerate Diagnostics, USA) is a fully automated test system that performs both identification and antimicrobial susceptibility testing (AST) directly from positive blood cultures within approximately 7 h. In total, 115 episodes of BSI with Gram-negative bacteria were included in our study and compared to conventional culture-based methods. The Accelerate Pheno system correctly identified 88.7% (102 of 115) of all BSI episodes and 97.1% (102 of 105) of isolates that are covered by the system's identification panel. The Accelerate Pheno system generated an AST result for 91.3% (95 of 104) samples in which the Accelerate Pheno system identified a Gram-negative pathogen. The overall category agreement between the Accelerate Pheno system and culture-based AST was 96.4%, the rates for minor discrepancies 1.4%, major discrepancies 2.3%, and very major discrepancies 1.0%. Of note, ceftriaxone, piperacillin-tazobactam, and carbapenem resistance was correctly detected in blood culture specimens with extended-spectrum beta-lactamase-producing Escherichia coli (n = 7) and multidrug-resistant Pseudomonas aeruginosa (n = 3) strains. The utilization of the Accelerate Pheno system reduced the time to result for identification by 27.49 h (P < 0.0001) and for AST by 40.39 h (P < 0.0001) compared to culture-based methods in our laboratory setting. In conclusion, the Accelerate Pheno system provided fast, reliable results while significantly improving turnaround time in blood culture diagnostics of Gram-negative BSI.

Marschal M ，Bachmaier J ，Autenrieth I ，Oberhettinger P ，Willmann M ，Peter S ... -  《-》