Accelerate Pheno™ system in sepsis by Gram-negative pathogens: four months of hospital experience

This study reports our experience with the Accelerate PhenoTM system (ACC) to guide management of patients with sepsis by Gram-negative pathogens. A diagnostic workflow, based on pathogen and resistance genes detection or ACC testing, was applied to 33 patients. Clinical and microbiological data were recorded, and analysis of broad-spectrum agents sparing was performed. Antimicrobial susceptibility results by ACC were available for 28 of 33 patients (84.85%). Among 434 microorganism-antimicrobial combinations, categorical agreement was 97.93%, very major errors 0.23%, major errors 1.15%, and minor errors 0.69%. Time to report (mean ± SD) of ACC results was 27.14 ± 6.90 h from sample collection, significantly shorter (p < 0.001, Δ = 19.96 h, 95% CI: 24.71 - 15.22) than that of the standard method (47.10 ± 11.92 h). A switch from empiric to targeted therapy was observed in 14 of 28 patients (50.0%), duration of empiric therapy was 37.73 ± 19.87 h, with a saving of 5.45 piperacillin/tazobactam and 5.28 carbapenems prescribed daily doses. Considering patients in which de-escalation would have been theoretically feasible, 27.69 prescribed daily doses of piperacillin/tazobactam and 19.08 of carbapenems could had been spared, compared to standard methods. In conclusion, ACC could impact positively on the management of septic patients by Gram-negative pathogens.